Chip 1998 September/CHIP Eylül 1998.iso/Slackwar/docs/Ethernet-HOWTO

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  Linux Ethernet-Howto
  by Paul Gortmaker
  v2.65, 1 February 1998

  This is the Ethernet-Howto, which is a compilation of information
  about which ethernet devices can be used for Linux, and how to set
  them up. It hopefully answers all the frequently asked questions about
  using ethernet cards with Linux. Note that this Howto is focused on
  the hardware and low level driver aspect of the ethernet cards, and
  does not cover the software end of things like ifconfig and route. See
  the Network Howto for that stuff.

  1.  Introduction

  The Ethernet-Howto covers what cards you should and shouldn't buy; how
  to set them up, how to run more than one, and other common problems
  and questions. It contains detailed information on the current level
  of support for all of the most common ethernet cards available.

  It does not cover the software end of things, as that is covered in
  the NET-2 Howto. Also note that general non-Linux specific questions
  about Ethernet are not (or at least they should not be) answered here.
  For those types of questions, see the excellent amount of information
  in the comp.dcom.lans.ethernet FAQ. You can FTP it from rtfm.mit.edu
  just like all the other newsgroup FAQs.

  This present revision covers distribution kernels up to and including
  2.0.33. Some information pertaining to development kernels up to
  version 2.1.82 is also included.

  The Ethernet-Howto is by:

       Paul Gortmaker, [e-mail]

  The primary source of information for the initial ASCII-only version
  of the Ethernet-Howto was:

       Donald J. Becker, [e-mail]

  who we should thank for writing the vast majority of ethernet card
  drivers that are presently available for Linux. He also is the
  original author of the NFS server too. Thanks Donald!

  Net-surfers may wish to check out the following URL:

  Donald Becker
  <http://cesdis.gsfc.nasa.gov/pub/people/becker/whoiam.html>

  Please see the Disclaimer and Copying information at the end of this
  document for information about redistribution of this document and the
  usual `we are not responsible for what you do...' legal type
  mumblings.

  1.1.  New Versions of this Document

  New versions of this document can be retrieved via anonymous FTP from:

  Sunsite HOWTO Archive <ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/>

  and various Linux ftp mirror sites. Updates will be made as new
  information and/or drivers becomes available. If this copy that you
  are reading is more than 6 months old, it is either out of date, or it
  means that I have been lazy and haven't updated it.

  If you have sent me an update and it is not included in the next
  release, it probably means I've lost it amongst the ton of junk e-mail
  I get. Please re-send it (along with an abusive message) and I will
  try and make sure it gets included in the next release.

  This document was produced by using the SGML system that was
  specifically set up for the Linux Howto project, and there are various
  output formats available, including, postscript, dvi, ascii, html, and
  soon TeXinfo.

  I would recommend viewing it in the html (via a WWW browser) or the
  Postscript/dvi format. Both of these contain cross-references that are
  lost in the ascii translation.

  If you want to get the official copy off sunsite, here is URL.

  Ethernet-HOWTO <http://sunsite.unc.edu/mdw/HOWTO/Ethernet-HOWTO.html>

  1.2.  Using the Ethernet-Howto

  As this guide is getting bigger and bigger, you probably don't want to
  spend the rest of your afternoon reading the whole thing. And the good
  news is that you don't have to read it all.

  Chances are you are reading this document beacuse you can't get things
  to work and you don't know what to do or check. The next section
  (``HELP - It doesn't work!'')  is aimed at newcomers to linux and will
  point you in the right direction.

  Typically the same problems and questions are asked over and over
  again by different people. Chances are your specific problem or
  question is one of these frequently asked questions, and is answered
  in the FAQ portion of this document .  (``The FAQ section'').
  Everybody should have a look through this section before posting for
  help.

  If you haven't got an ethernet card, then you will want to start with
  deciding on a card.  (``What card should I buy...'')

  If you have already got an ethernet card, but are not sure if you can
  use it with Linux, then you will want to read the section which
  contains specific information on each manufacturer, and their cards.
  (``Vendor Specific...'')

  If you are interested in some of the technical aspects of the Linux
  device drivers, then you can have a browse of the section with this
  type of information.  (``Technical Information'')

  1.3.  HELP - It doesn't work!

  Okay, don't panic. This will lead you through the process of getting
  things working, even if you have no prior background in linux or
  ethernet hardware.

  First thing you need to do is figure out what model your card is so
  you can determine if Linux has a driver for that particular card.
  Different cards typically have different ways of being controlled by
  the host computer, and the linux driver (if there is one) contains
  this control information in a format that allows linux to use the
  card.  If you don't have any manuals or anything of the sort that tell
  you anything about the card model, then you can try the section on
  helping with mystery cards (reference section: ``Identifying an
  Unknown Card'').

  Now that you know what type of card you have, read through the details
  of your particular card in the card specific section (reference
  section: ``Vendor Specific...'')  which lists in alphabetical order,
  card manufacturers, individual model numbers and whether it has a
  linux driver or not. If it lists it as `Not Supported' you can pretty
  much give up here. If you can't find your card in that list, then
  check to see if your card manual lists it as being `compatible' with
  another known card type. For example there are hundreds, if not
  thousands of different cards made to be compatible with the original
  Novell NE2000 design.

  Assuming you have found out that your card does have a linux driver,
  you now need to go back to the CD-ROM or whatever you installed from,
  and find the list of pre-built kernels that comes with it. The kernel
  is the core operating system that is first loaded at boot, and
  contains drivers for various pieces of hardware, among other things.
  Just because linux has a driver for your card does not mean that it is
  built into every kernel. Depending on who made the CD-ROM, there may
  be only a few pre-built kernels, and a whole bunch of drivers as
  smaller separate modules, or there may be a whole lot of kernels,
  covering a vast combination of built-in driver combinations. Hopefully
  there will also be a text file with them that lists what drivers are
  included into which kernels. Try and find a kernel that is listed as
  having the driver you need as built into it, or try and find a module
  with the name of the driver you need.

  If you found a pre-built kernel that has your driver in it, you will
  want to boot that kernel instead of the one you are presently using.
  Most linux systems use LILO to boot, and will have installed the LILO
  documentation on your system.  Follow the instructions in that for
  booting another kernel, as they are beyond the scope of this document.

  If you instead found a small module that contains the driver, you will
  need to attach this module to the kernel after it has booted up. See
  the information that came with your distribution on installing and
  using modules, along with the module section in this document.
  (``Using the Ethernet Drivers as Modules'')

  If you didn't find either a pre-built kernel with your driver, or a
  module form of the driver, chances are you have a typically uncommon
  card, and you will have to build your own kernel with that driver
  included. Once you have linux installed, building a custom kernel is
  not difficult at all. You essentially answer yes or no to what you
  want the kernel to contain, and then tell it to build it. There is a
  Kernel-HowTo that will help you along.

  At this point you should have somehow managed to be booting a kernel
  with your driver built in, or be loading it as a module.  About half
  of the problems people have are related to not having driver loaded
  one way or another, so you may find things work now.

  If it still doesn't work, then you need to verify that the kernel is
  indeed detecting the card. To do this, you need to type dmesg | more
  when  logged in after the system has booted and all modules have been
  loaded.  This will allow you to review the boot messages that the
  kernel scrolled up the screen during the boot process.  If the card
  has been detected, you should see somewhere in that list a message
  from your card's driver that starts with eth0, mentions the driver
  name and the hardware parameters (interrupt setting, input/output port
  address, etc) that the card is set for. If you don't see a message
  like this, then the driver didn't detect your card, and that is why
  things aren't working. See the FAQ (``The FAQ Section'') for what to
  do if your card is not detected. If you have a NE2000 compatible,
  there is also some NE2000 specific tips on getting a card detected in
  the FAQ section as well.

  If the card is detected, but the detection message reports some sort
  of error, like a resource conflict, then the driver probably won't
  have initialized properly and the card still wont be useable. Most
  common error messages of this sort are also listed in the FAQ section,
  along with a solution.

  If the detection message seems okay, then double check the card
  resources reported by the driver against those that the card is
  physically set for (either by little black jumpers on the card, or by
  a software utility supplied by the card manufacturer.)  These must
  match exactly. For example, if you have the card jumpered or
  configured to IRQ 15 and the driver reports IRQ 10 in the boot
  messages, things will not work. The FAQ section discusses the most
  common cases of drivers incorrectly detecting the configuration
  information of various cards.

  At this point, you have managed to get you card detected with all the
  correct parameters, and hopefully everything is working.  If not, then
  you either have a software configuration error, or a hardware
  configuration error. A software configuration error is not setting up
  the right network addresses for the ifconfig and route commands, and
  details of how to do that are fully described in the Network HowTo and
  the `Network Administrator's Guide' which both probably came on the
  CD-ROM you installed from.

  A hardware configuration error is when some sort of resource conflict
  or mis-configuration (that the driver didn't detect at boot) that
  stops the card from working properly. This typically can be observed
  in one of three different ways. (1) You get an error message when
  ifconfig tries to open the device for use, such as ``SIOCSFFLAGS: Try
  again''. (2) The driver reports eth0 error messages (viewed by dmesg |
  more) or strange inconsistencies for each time it tries to send or
  receive data. (3) Typing cat /proc/net/dev shows non-zero numbers in
  one of the errs, drop, fifo, frame or carrier columns for eth0.  Most
  of the typical hardware configuration errors are also discussed in the
  FAQ section.

  Well, if you have got to this point and things still aren't working,
  read the FAQ section of this document, read the vendor specific
  section detailing your particular card, and if it still doesn't work
  then you may have to resort to posting to an appropriate newsgroup for
  help. If you do post, please detail all relevant information in that
  post, such as the card brand, the kernel version, the driver boot
  messages, the output from cat /proc/net/dev, a clear description of
  the problem, and of course what you have already tried to do in an
  effort to get things to work.

  You would be surprised at how many people post useless things like
  ``Can someone help me? My ethernet doesn't work.'' and nothing else.
  Readers of the newsgroups tend to ignore such silly posts, whereas a
  detailed and informational problem description may allow a `linux-
  guru' to spot your problem right away.

  2.  What card should I buy for Linux?

  The answer to this question depends heavily on exactly what you intend
  on doing with your net connection, and how much traffic it will see.

  If you only expect a single user to be doing the occasional ftp
  session or WWW connection, then an old 8 bit card will probably keep
  you happy.

  If you intend to set up a server, and you require the CPU overhead of
  Rx'ing and Tx'ing ether packets to be kept at a minimum, you probably
  want to look at one of the newer PCI cards with the DEC 21040 chip, or
  the AMD PCnet-PCI chip.

  If you fall somewhere in the middle of the above, then any one of the
  16 bit ISA cards with stable drivers will do the job for you.

  2.1.  So What Drivers are Stable?

  Of the 16 bit ISA cards, the following drivers are very mature, and
  you shouldn't have any problems if you buy a card that uses these
  drivers.

  SMC-Ultra/EtherEZ, WD80x3, 3c509, 3c503/16, Lance, NE2000.

  This is not to say that all the other drivers are unstable.  It just
  happens that the above are the oldest and most used of all the linux
  drivers, making them the safest choice.

  Note that some el-cheapo motherboards can have trouble with the bus-
  mastering that the lance cards do, and some el-cheapo NE2000 clones
  can have trouble getting detected at boot.

  As for PCI cards, the PCnet-PCI cards that use the lance driver are a
  safe choice (except for the Boca cards as they have hardware flaws).
  The Allied Telsyn AT2450 is a PCnet-PCI implementation that is known
  to work well.

  The DEC 21040 `tulip' driver and the 3c59x `vortex' driver are
  relatively new drivers, but have proven themselves to be quite stable
  already.

  2.2.  Eight bit vs 16 bit Cards

  You probably can't buy a new 8 bit ISA ethercard anymore, but you will
  find lots of them turning up at computer swap meets and the like for
  the next few years, at very low prices.  This will make them popular
  for ``home-ethernet'' systems.

  Some 8 bit cards that will provide adequate performance for light to
  average use are the wd8003, the 3c503 and the ne1000.  The 3c501
  provides poor performance, and these poor 12 year old relics of the XT
  days should be avoided.

  The 8 bit data path doesn't hurt performance that much, as you can
  still expect to get about 500 to 800kB/s ftp download speed to an 8
  bit wd8003 card (on a fast ISA bus) from a fast host.  And if most of
  your net-traffic is going to remote sites, then the bottleneck in the
  path will be elsewhere, and the only speed difference you will notice
  is during net activity on your local subnet.

  2.3.  32 Bit / VLB / PCI Ethernet Cards

  There aren't many 32 bit ethercard device drivers because there aren't
  that many 32 bit ethercards.  There aren't many 32 bit ethercards out
  there because a 10Mbs network doesn't justify spending a large price
  increment for the 32 bit interface. Now that 100Mbs networks are
  becoming more common, this is changing though.

  See ``Programmed I/O vs. ...'' as to why having a 10Mbps ethercard on
  an 8MHz ISA bus is really not a bottleneck. Even though having the
  ethercard on a fast bus won't necessarily mean faster transfers, it
  will usually mean reduced CPU overhead, which is good for multi-user
  systems.

  AMD has the 32 bit PCnet-VLB and PCnet-PCI chips.  See ``AMD
  PCnet-32'' for info on the 32 bit versions of the LANCE / PCnet-ISA
  chip.

  The DEC 21040 PCI chip is another option (see ``DEC 21040'') for
  power-users.  Many manufacturers produce cards that use this chip, and
  the prices of such no-name cards is usually quite cheap.

  3Com's `Vortex' and `Boomerang' PCI cards are also another option, and
  the price is quite cheap if you can get one under their evaluation
  deal while it lasts.  (see ``3c590/3c595'')

  Various clone manufacturers have started making PCI ne2000 clones
  based on a RealTek or Winbond chip. These cards are also supported by
  the linux ne2000 driver for v2.0.31 and newer kernels.  However you
  only benefit from the faster bus interface, as the card is still using
  the age-old ne2000 driver interface.

  2.4.  Available 100Mbs Cards and Drivers

  The present list of supported 100Mbs hardware is as follows: cards
  with the DEC 21140 chip; the 3c595/3c90x Vortex cards; and the HP
  100VG ANY-LAN. The drivers for the first two are quite stable, but
  feedback on the HP driver has been low so far.

  The EtherExpressPro10/100B now also has a driver in the current v2.0
  kenrel. For updates and/or support, see the relevant section in this
  document.

  The 21140 100Base-? chip is supported with the same driver as its
  10Mbs counterpart, the 21040. SMC's 100Mbs EtherPower PCI card uses
  this chip. As with the 21040, you have a choice of two drivers to pick
  from.

  Also have a look at the information on Donald's WWW site, at the
  following URL:

  100Mbs Ethernet <http://cesdis.gsfc.nasa.gov/linux/misc/100mbs.html>

  Donald had done a fair bit of work with the SMC EtherPower-10/100
  cards, and reported getting about 4.6MB/s application to application
  with TCP on P5-100 Triton machines.

  (See ``3c595'' and ``DEC 21140'' for more details.)

  For 100VG information, see the following section, and this URL on
  Donald's Site:

  Donald's 100VG Page
  <http://cesdis.gsfc.nasa.gov/linux/drivers/100vg.html>

  You may also be interested in looking at:

  Dan Kegel's Fast Ethernet Page <http://alumni.caltech.edu/~dank/fe/>

  2.5.  100VG versus 100BaseT

  The following blurb from yet another one of Donald's informative
  comp.os.linux postings summarizes the situation quite well:

  ``For those not in the know, there are two competing 100Mbs ethernet
  standards, 100VG (aka 100baseVG and 100VG-AnyLAN) and 100baseT (with
  100baseTx, 100baseT4 and 100baseFx cable types).

  100VG was on the market first, and I feel that it is better engineered
  than 100baseTx.  I was rooting for it to win, but it clearly isn't
  going to.  HP et al. made several bad choices:

  1) Delaying the standard so that they could accommodate IBM and
  support token ring frames.  It `seemed like a good idea at the time',
  since it would enable token ring shops to upgrade without the managers
  having to admit they made a very expensive mistake committing to the
  wrong technology.  But there was nothing to be gained, as the two
  frame types couldn't coexist on a network, token ring is a morass of
  complexity, and IBM went with 100baseT anyway.

  2) Producing only ISA and EISA cards.  (A PCI model was only recently
  announced.)  The ISA bus is too slow for 100mbs, and relatively few
  EISA machines exist.  At the time VLB was common, fast, and cheap with
  PCI a viable choice.  But "old-timer" wisdom held that servers would
  stay with the more expensive EISA bus.

  3) Not sending me a databook.  Yes, this action was the real reason
  for the 100VGs downfall :-).  I called all over for programming info,
  and all I could get was a few page color glossy brochure from AT&T
  describing how wonderful the Regatta chipset was.''

  2.6.  Programmed I/O vs. Shared Memory vs. DMA

  Ethernet is 10Mbs. (Don't be pedantic, 3Mbs and 100Mbs don't count.)
  If you can already send and receive back-to-back packets, you just
  can't put more bits over the wire. Every modern ethercard can receive
  back-to-back packets. The Linux DP8390 drivers (wd80x3, SMC-Ultra,
  3c503, ne2000, etc) come pretty close to sending back-to-back packets
  (depending on the current interrupt latency) and the 3c509 and AT1500
  hardware have  no problem at all automatically sending back-to-back
  packets.

  The ISA bus can do 5.3MB/sec (42Mb/sec), which sounds like more than
  enough. You can use that bandwidth in several ways, listed below.

  2.6.1.  Programmed I/O (e.g. NE2000, 3c509)

  Pro: Doesn't use any constrained system resources, just a few I/O
  registers, and has no 16M limit.

  Con: Usually the slowest transfer rate, the CPU is waiting the whole
  time, and interleaved packet access is usually difficult to
  impossible.

  2.6.2.  Shared memory (e.g. WD80x3, SMC-Ultra, 3c503)

  Pro: Simple, faster than programmed I/O, and allows random access to
  packets. The linux drivers compute the checksum of incoming IP packets
  as they are copied off the card, resulting in a further reduction of
  CPU usage vs. an equivalent PIO card.

  Con: Uses up memory space (a big one for DOS users, essentially a non-
  issue under Linux), and it still ties up the CPU.

  2.6.3.  Slave (normal) Direct Memory Access (e.g. none for Linux!)

  Pro: Frees up the CPU during the actual data transfer.

  Con: Checking boundary conditions, allocating contiguous buffers, and
  programming the DMA registers makes it the slowest of all techniques.
  It also uses up a scarce DMA channel, and requires aligned low memory
  buffers.

  2.6.4.  Bus Master Direct Memory Access (e.g. LANCE, DEC 21040)

  Pro: Frees up the CPU during the data transfer, can string together
  buffers, can require little or no CPU time lost on the ISA bus.

  Con: Requires low-memory buffers and a DMA channel. Any bus-master
  will have problems with other bus-masters that are bus-hogs, such as
  some primitive SCSI adaptors. A few badly-designed motherboard
  chipsets have problems with bus-masters. And a reason for not using
  any type of DMA device is using a 486 processor designed for plug-in
  replacement of a 386: these processors must flush their cache with
  each DMA cycle. (This includes the Cx486DLC, Ti486DLC, Cx486SLC,
  Ti486SLC, etc.)

  2.7.  Type of cable that your card should support

  If you are setting up a small ``personal'' network, you will probably
  want to use thinnet or thin ethernet cable. This is the style with the
  standard BNC connectors. See ``Cables, Coax...''  for other concerns
  with different types of ethernet cable.

  Most ethercards also come in a `Combo' version for only $10-$20 more.
  These have both twisted pair and thinnet transceiver built-in,
  allowing you to change your mind later.

  The twisted pair cables, with the RJ-45 (giant phone jack) connectors
  is technically called 10BaseT. You may also hear it called UTP
  (Unsheilded Twisted Pair).

  The thinnet, or thin ethernet cabling, (RG-58 coaxial cable) with the
  BNC (metal push and turn-to-lock) connectors is technically called
  10Base2.

  The older thick ethernet (10mm coaxial cable) which is only found in
  older installations is called 10Base5.

  Large corporate installations will most likely use 10BaseT instead of
  10Base2. 10Base2 does not offer an easy upgrade path to the new
  upcoming 100Base-whatever.

  3.  Frequently Asked Questions

  Here are some of the more frequently asked questions about using Linux
  with an Ethernet connection. Some of the more specific questions are
  sorted on a `per manufacturer basis'.  However, since this document is
  basically `old' by the time you get it, any `new' problems will not
  appear here instantly. For these, I suggest that you make efficient
  use of your newsreader. For example, nn users would type

       nn -xX -s'3c'

  to get all the news articles in your subscribed list that have `3c' in
  the subject. (ie. 3com, 3c509, 3c503, etc.)  The moral: Read the man
  page for your newsreader.

  3.1.  Alpha Drivers -- Getting and Using them

  I heard that there is an updated or alpha driver available for my
  card. Where can I get it?

  The newest of the `new' drivers can be found on Donald's ftp site:
  cesdis.gsfc.nasa.gov in the /pub/linux/ area. Things change here quite
  frequently, so just look around for it.  Alternatively, it may be
  easier to use a WWW browser on:

  Don's Linux Home Page
  <http://cesdis.gsfc.nasa.gov/pub/linux/linux.html>

  to locate the driver that you are looking for. (Watch out for WWW
  browsers that silently munge the source by replacing TABs with spaces
  and so on - use ftp, or at least an FTP URL for downloading if
  unsure.)

  Now, if it really is an alpha, or pre-alpha driver, then please treat
  it as such. In other words, don't complain because you can't figure
  out what to do with it. If you can't figure out how to install it,
  then you probably shouldn't be testing it.  Also, if it brings your
  machine down, don't complain. Instead, send us a well documented bug
  report, or even better, a patch!

  Note that some of the `useable' experimental/alpha drivers have been
  included in the standard kernel source tree. When running make config
  one of the first things you will be asked is whether to ``Prompt for
  development and/or incomplete code/drivers''.  You will have to answer
  `Y' here to get asked about including any alpha/experiemntal drivers.

  3.2.  Using More than one Ethernet Card per Machine

  What needs to be done so that Linux can run two ethernet cards?

  The hooks for multiple ethercards are all there.  However, note that
  at the moment only one ethercard is auto-probed for by default.  This
  helps to avoid possible boot time hangs caused by probing sensitive
  cards.

  There are two ways that you can enable auto-probing for the second
  (and third, and...) card. The easiest method is to pass boot-time
  arguments to the kernel, which is usually done by LILO. Probing for
  the second card can be achieved by using a boot-time argument as
  simple as ether=0,0,eth1. In this case eth0 and eth1 will be assigned
  in the order that the cards are found at boot.  Say if you want the
  card at 0x300 to be eth0 and the card at 0x280 to be eth1 then you
  could use

       LILO: linux ether=5,0x300,eth0 ether=15,0x280,eth1

  The ether= command accepts more than the IRQ + i/o + name shown above.
  Please have a look at ``Passing Ethernet Arguments...''  for the full
  syntax, card specific parameters, and LILO tips.

  These boot time arguments can be made permanent so that you don't have
  to re-enter them every time. See the LILO configuration option
  `append' in the LILO manual.

  The second way (not recommended) is to edit the file Space.c and
  replace the 0xffe0 entry for the i/o address with a zero. The 0xffe0
  entry tells it not to probe for that device -- replacing it with a
  zero will enable autoprobing for that device.

  Note that if you are intending to use Linux as a gateway between two
  networks, you will have to re-compile a kernel with IP forwarding
  enabled. Usually using an old AT/286 with something like the `kbridge'
  software is a better solution.

  If you are viewing this while net-surfing, you may wish to look at a
  mini-howto Donald has on his WWW site. Check out Multiple Ethercards
  <http://cesdis.gsfc.nasa.gov/linux/misc/multicard.html>.

  For module users with 8390 based cards, you can have a single module
  control multiple cards  of the same brand. Please see ``8390 Based
  Cards as Modules'' for module specific information about using
  multiple cards.

  3.3.  Poor NE2000 Clones

  Here is a list of some of the NE-2000 clones that are known to have
  various problems. Most of them aren't fatal. In the case of the ones
  listed as `bad clones' -- this usually indicates that the cards don't
  have the two NE2000 identifier bytes. NEx000-clones have a Station
  Address PROM (SAPROM) in the packet buffer memory space.  NE2000
  clones have 0x57,0x57 in bytes 0x0e,0x0f of the SAPROM, while other
  supposed NE2000 clones must be detected by their SA prefix.

  This is not a comprehensive list of all the NE2000 clones that don't
  have the 0x57,0x57 in bytes 0x0e,0x0f of the SAPROM. There are
  probably hundreds of them. If you get a card that causes the driver to
  report an `invalid signature' then you will have to add your cards
  signature to the driver. The process for doing this is described
  below.

  Accton NE2000 -- might not get detected at boot, see below.

  Artisoft LANtastic AE-2 -- OK, but has flawed error-reporting
  registers.

  AT-LAN-TEC NE2000 -- clone uses Winbond chip that traps SCSI drivers

  ShineNet LCS-8634 -- clone uses Winbond chip that traps SCSI drivers

  Cabletron E10**, E20**, E10**-x, E20**-x -- bad clones, but the driver
  checks for them. See ``E10**''.

  D-Link Ethernet II -- bad clones, but the driver checks for them. See
  ``DE-100 / DE-200''.

  DFI DFINET-300, DFINET-400 -- bad clones, but the driver checks for
  them. See ``DFI-300 / DFI-400''

  EtherNext UTP8, EtherNext UTP16 -- bad clones, but the driver checks
  for them.

  3.4.  Problems with NE1000 / NE2000 cards (and clones)

  Problem: PCI NE2000 clone card is not detected at boot with v2.0.x.

  Reason: The ne.c driver up to v2.0.30 only knows about the PCI ID
  number of RealTek 8029 based clone cards. Since then, Winbond and
  Compex have also released PCI NE2000 clone cards, with different PCI
  ID numbers, and hence the driver doesn't detect them.

  Solution: The easiest solution is to upgrade to a v2.0.31 (or newer)
  version of the linux kernel. It knows the ID numbers of about five
  different NE2000-PCI chips, and will detect them automatically at boot
  or at module loading time.

  Alternatively, after booting, you can get the I/O address (and
  interrupt) that the card will use from a  ``cat /proc/pci''.  Say for
  example it reports IRQ 9 and I/O at 0xffe0, then at the LILO boot
  prompt you can add ether=9,0xffe0,eth0 which will point the driver
  right at your card and avoid the PCI based probing altogether. (Future
  v2.1+ kernels will know about the PCI IDs of Winbond and Compex NE2000
  clones as well, so this won't be necessary then.)

  Problem: PCI NE2000 clone card is reported as an ne1000 (8 bit card!)
  at boot or when I load the ne.o module for v2.0.x, and hence doesn't
  work.

  Reason: Some PCI clones don't implement byte wide access (and hence
  are not truly 100% NE2000 compatible). This causes the probe to think
  they are NE1000 cards if the PCI probing wasn't used (which it isn't
  when an explicit I/O address is given with the module or at boot.)

  Solution: You can upgrade to v2.0.31 (or newer) as described above, or
  manually make the following change to drivers/net/ne.c:

  ______________________________________________________________________
  -       if (pci_irq_line)
  +       if (pci_irq_line || ioaddr >= 0x400)
              wordlength = 2;   /* Catch broken PCI cards mentioned above. */
  ______________________________________________________________________

  and then recompile the module (or the kernel). Note that v2.0.31 and
  recent v2.1.x revisons do not require an I/O address for detecting
  most PCI cards at boot or with the ne.o module - it is best to let it
  autodetect the card with these versions.

  Problem: PCI NE2000 card gets terrible performance, even when reducing
  the window size as described in the Performance Tips section.

  Reason: The spec sheets for the original 8390 chip,  desgined and sold
  over ten years ago, noted that a dummy read from the chip was required
  before the write operation for maximum reliablity.  The driver has the
  facility to do this but it has been disabled by default since the v1.2
  days, once the real problem causing the crashes back then was located.
  One user has reported that re-enabling this `mis-feature' helped their
  performance with a cheap PCI NE2000 clone card.

  Solution: Since it has only been reported as a solution by one person,
  don't get your hopes up. Re-enabling the read before write fix is done
  by simply editing the file linux/drivers/net/ne.c, uncommenting the
  line containing NE_RW_BUGFIX and then rebuilding the kernel or module
  as appropriate. Please send an e-mail describing the performance
  difference and type of card/chip you have if this helps you.

  Problem: NE*000 card hangs machine, sometimes with a `DMA conflict'
  message, sometimes completely silently.

  Reason: There were some bugs in the driver and the upper networking
  layers that caused this. They have been fixed long ago, in kernels
  v1.2.9 and above. Upgrade your kernel.

  Problem: NE*000 card hangs machine during NE probe, or can not read
  station address properly.

  Reason: Kernels previous to v1.3.7 did not fully reset the card after
  finding it at boot. Some cheap cards are not left in a reasonable
  state after power-up and need to be fully reset before any attempt is
  made to use them. Also, a previous probe may have upset the NE card
  prior to the NE probe taking place. In that case, look in to using the
  ``reserve='' boot keyword to protect the card from other probes.

  Problem: NE*000 driver reports `not found (no reset ack)' during boot
  probe.

  Reason: This is related to the above change. After the initial
  verification that an 8390 is at the probed i/o address, the reset is
  performed. When the card has completed the reset, it is supposed to
  acknowedge that the reset has completed.  Your card doesn't, and so
  the driver assumes that no NE card is present.

  Solution: You can tell the driver that you have a bad card by using an
  otherwise unused mem_end hexidecimal value of 0xbad at boot time. You
  have to also supply a non-zero i/o base for the card when using the
  0xbad override. For example, a card that is at 0x340 that doesn't ack
  the reset would use something like:

       LILO: linux ether=0,0x340,0,0xbad,eth0

  This will allow the card detection to continue, even if your card
  doesn't ACK the reset. If you are using the driver as a module, then
  you can supply the option bad=0xbad just like you supply the I/O
  address. Note that v2.0.x modules won't understand the bad= option, as
  it was added during the v2.1 development.

  Problem: NE*000 card hangs machine at first network access.

  Reason: This problem has been reported for kernels as old as 1.1.57 to
  the present. It appears confined to a few software configurable clone
  cards. It appears that they expect to be initialized in some special
  way.

  Solution: Several people have reported that running the supplied DOS
  software config program and/or the supplied DOS driver prior to warm
  booting (i.e. loadlin or the `three-finger-salute') into linux allowed
  the card to work. This would indicate that these cards need to be
  initialized in a particular fashion, slightly different than what the
  present Linux driver does.

  Problem: NE*000 ethercard at 0x360 doesn't get detected anymore.

  Reason: Recent kernels ( > 1.1.7X) have more sanity checks with
  respect to overlapping i/o regions. Your NE2000 card is 0x20 wide in
  i/o space, which makes it hit the parallel port at 0x378.  Other
  devices that could be there are the second floppy controller (if
  equipped) at 0x370 and the secondary IDE controller at 0x376--0x377.
  If the port(s) are already registered by another driver, the kernel
  will not let the probe happen.

  Solution: Either move your card to an address like 0x280, 0x340, 0x320
  or compile without parallel printer support.

  Problem: Network `goes away' every time I print something (NE2000)

  Reason: Same problem as above, but you have an older kernel that
  doesn't check for overlapping i/o regions. Use the same fix as above,
  and get a new kernel while you are at it.

  Problem: NE*000 ethercard probe at 0xNNN: 00 00 C5 ... not found.
  (invalid signature yy zz)

  Reason: First off, do you have a NE1000 or NE2000 card at the addr.
  0xNNN?  And if so, does the hardware address reported look like a
  valid one? If so, then you have a poor NE*000 clone. All NE*000 clones
  are supposed to have the value 0x57 in bytes 14 and 15 of the SA PROM
  on the card. Yours doesn't -- it has `yy zz' instead.

  Solution: There are two ways to get around this. The easiest is to use
  an 0xbad mem_end value as described  above for the `no reset ack'
  problem. This will bypass the signature check, as long as a non-zero
  i/o base is also given. This way no recompilation of the kernel is
  required.

  The second method involves changing the driver itself, and then
  recompiling your kernel.  The driver (/usr/src/linux/drivers/net/ne.c)
  has a "Hall of Shame" list at about line 42. This list is used to
  detect poor clones.  For example, the DFI cards use `DFI' in the first
  3 bytes of the PROM, instead of using 0x57 in bytes 14 and 15, like
  they are supposed to.

  You can determine what the first 3 bytes of your card PROM are by
  adding a line like:

      printk("PROM prefix: %2.2x %2.2x %2.2x\n",SA_prom[0],SA_prom[1],SA_prom[2]);

  into the driver, right after the error message you got above, and just
  before the "return ENXIO" at line 227.

  Reboot with this change in place, and after the detection fails, you
  will get the three bytes from the PROM like the DFI example above.
  Then you can add your card to the bad_clone_list[] at about line 43.
  Say the above line printed out:

  PROM prefix: 0x3F 0x2D 0x1C

  after you rebooted. And say that the 8 bit version of your card was
  called the "FOO-1k" and the 16 bit version the "FOO-2k". Then you
  would add the following line to the bad_clone_list[]:

       {"FOO-1k", "FOO-2k", {0x3F, 0x2D, 0x1C,}},

  Note that the 2 name strings you add can be anything -- they are just
  printed at boot, and not matched against anything on the card.  You
  can also take out the "printk()" that you added above, if you want.
  It shouldn't hit that line anymore anyway. Then recompile once more,
  and your card should be detected.

  Problem: Errors like DMA address mismatch

  Is the chip a real NatSemi 8390? (DP8390, DP83901, DP83902 or
  DP83905)?  If not, some clone chips don't correctly implement the
  transfer verification register. MS-DOS drivers never do error
  checking, so it doesn't matter to them. (Note: The DMA address check
  is not done by default as of v1.2.4 for performance reasons. Enable it
  with the `NE_SANITY' define in ne.c if you want the check done.)

  Are most of the messages off by a factor of 2?  If so:  Are you using
  the NE2000 in a 16 bit slot?  Is it jumpered to use only 8 bit
  transfers?

  The Linux driver expects a NE2000 to be in a 16 bit slot. A NE1000 can
  be in either size slot. This problem can also occur with some clones,
  notably older D-Link 16 bit cards, that don't have the correct ID
  bytes in the station address PROM.

  Are you running the bus faster than 8Mhz?  If you can change the speed
  (faster or slower), see if that makes a difference. Most NE2000 clones
  will run at 16MHz, but some may not. Changing speed can also mask a
  noisy bus.

  What other devices are on the bus?  If moving the devices around
  changes the reliability, then you have a bus noise problem -- just
  what that error message was designed to detect. Congratulations,
  you've probably found the source of other problems as well.

  Problem: The machine hangs during boot right after the `8390...'  or
  `WD....' message. Removing the NE2000 fixes the problem.

  Solution: Change your NE2000 base address to something like 0x340.
  Alternatively, you can use the ``reserve='' boot argument in
  conjunction with the ``ether='' argument to protect the card from
  other device driver probes.

  Reason: Your NE2000 clone isn't a good enough clone. An active NE2000
  is a bottomless pit that will trap any driver autoprobing in its
  space.  Changing the NE2000 to a less-popular address will move it out
  of the way of other autoprobes, allowing your machine to boot.

  Problem: The machine hangs during the SCSI probe at boot.

  Reason: It's the same problem as above, change the ethercard's
  address, or use the reserve/ether boot arguments.

  Problem: The machine hangs during the soundcard probe at boot.

  Reason: No, that's really during the silent SCSI probe, and it's the
  same problem as above.

  Problem: NE2000 not detected at boot - no boot messages at all

  Solution: There is no `magic solution' as there can be a number of
  reasons why it wasn't detected. The following list should help you
  walk through the possible problems.

  1) Build a new kernel with only the device drivers that you need.
  Verify that you are indeed booting the fresh kernel. Forgetting to run
  lilo, etc. can result in booting the old one. (Look closely at the
  build time/date reported at boot.) Sounds obvious, but we have all
  done it before. Make sure the driver is in fact included in the new
  kernel, by checking the System.map file for names like ne_probe.

  2) Look at the boot messages carefully. Does it ever even mention
  doing a ne2k probe such as `NE*000 probe at 0xNNN: not found (blah
  blah)' or does it just fail silently. There is a big difference.  Use
  dmesg|more to review the boot messages after logging in, or hit Shift-
  PgUp to scroll the screen up after the boot has completed and the
  login prompt appears.

  3) After booting, do a cat /proc/ioports and verify that the full
  iospace that the card will require is vacant. If you are at 0x300 then
  the ne2k driver will ask for 0x300-0x31f. If any other device driver
  has registered even one port anywhere in that range, the probe will
  not take place at that address and will silently continue to the next
  of the probed addresses. A common case is having the lp driver reserve
  0x378 or the second IDE channel reserve 0x376 which stops the ne
  driver from probing 0x360-0x380.

  4) Same as above for cat /proc/interrupts. Make sure no other device
  has registered the interrupt that you set the ethercard for. In this
  case, the probe will happen, and the ether driver will complain loudly
  at boot about not being able to get the desired IRQ line.

  5) If you are still stumped by the silent failure of the driver, then
  edit it and add some printk() to the probe. For example, with the ne2k
  you could add/remove lines (marked with a `+' or `-') in net/ne.c
  like:

  ______________________________________________________________________
      int reg0 = inb_p(ioaddr);

  +    printk("NE2k probe - now checking %x\n",ioaddr);
  -    if (reg0 == 0xFF)
  +    if (reg0 == 0xFF) {
  +       printk("NE2k probe - got 0xFF (vacant i/o port)\n");
          return ENODEV;
  +    }
  ______________________________________________________________________

  Then it will output messages for each port address that it checks, and
  you will see if your card's address is being probed or not.

  6) You can also get the ne2k diagnostic from Don's ftp site (mentioned
  in the howto as well) and see if it is able to detect your card after
  you have booted into linux. Use the `-p 0xNNN' option to tell it where
  to look for the card. (The default is 0x300 and it doesn't go looking
  elsewhere, unlike the boot-time probe.)  The output from when it finds
  a card will look something like:

  ______________________________________________________________________
  Checking the ethercard at 0x300.
    Register 0x0d (0x30d) is 00
    Passed initial NE2000 probe, value 00.
  8390 registers: 0a 00 00 00 63 00 00 00 01 00 30 01 00 00 00 00
  SA PROM  0: 00 00 00 00 c0 c0 b0 b0 05 05 65 65 05 05 20 20
  SA PROM 0x10: 00 00 07 07 0d 0d 01 01 14 14 02 02 57 57 57 57

          NE2000 found at 0x300, using start page 0x40 and end page 0x80.
  ______________________________________________________________________

  Your register values and PROM values will probably be different.  Note
  that all the PROM values are doubled for a 16 bit card, and that the
  ethernet address (00:00:c0:b0:05:65) appears in the first row, and the
  double 0x57 signature appears at the end of the PROM.

  The output from when there is no card installed at 0x300 will look
  something like this:

  ______________________________________________________________________
  Checking the ethercard at 0x300.
    Register 0x0d (0x30d) is ff
    Failed initial NE2000 probe, value ff.
  8390 registers: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  SA PROM        0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  SA PROM 0x10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

   Invalid signature found, wordlength 2.
  ______________________________________________________________________

  The 0xff values  arise because that is the value that is returned when
  one reads a vacant i/o port. If you happen to have some other hardware
  in the region that is probed, you may see some non 0xff values as
  well.

  7) Try warm booting into linux from a DOS boot floppy (via loadlin)
  after running the supplied DOS driver or config program. It may be
  doing some extra (i.e. non-standard) "magic" to initialize the card.

  8) Try Russ Nelson's ne2000.com packet driver to see if even it can
  see your card -- if not, then things do not look good. Example:

       A:> ne2000 0x60 10 0x300

  The arguments are software interrupt vector, hardware IRQ, and  i/o
  base.  You can get it from any msdos archive in pktdrv11.zip -- The
  current version may be newer than 11.

  3.5.  Problems with SMC Ultra/EtherEZ and WD80*3 cards

  Problem: You get messages such as the following:

          eth0: bogus packet size: 65531, status=0xff, nxpg=0xff

  Reason: There is a shared memory problem.

  Solution: The most common reason for this is PCI machines that are not
  configured to map in ISA memory devices. Hence you end up reading the
  PC's RAM (all 0xff values) instead of the RAM on the card that
  contains the data from the received packet.

  Other typical problems that are easy to fix are board conflicts,
  having cache or `shadow ROM' enabled for that region, or running your
  ISA bus faster than 8Mhz. There are also a surprising number of memory
  failures on ethernet cards, so run a diagnostic program if you have
  one for your ethercard.

  Problem: SMC EtherEZ doesn't work in non-shared memory (PIO) mode.

  Reason: Older versions of the Ultra driver only supported the card in
  the shared memory mode of operation.

  Solution: The driver in kernel version 2.0 and above also supports the
  programmed i/o mode of operation. Upgrade to v2.0, or get the drop-in
  replacement for kernel v1.2.13 from Donald's ftp/www site.

  Problem: Old wd8003 and/or jumper-settable wd8013 always get the IRQ
  wrong.

  Reason: The old wd8003 cards and jumper-settable wd8013 clones don't
  have the EEPROM that the driver can read the IRQ setting from.  If the
  driver can't read the IRQ, then it tries to auto-IRQ to find out what
  it is. And if auto-IRQ returns zero, then the driver just assigns IRQ
  5 for an 8 bit card or IRQ 10 for a 16 bit card.

  Solution: Avoid the auto-IRQ code, and tell the kernel what the IRQ
  that you have jumpered the card to is via a boot time argument.  For
  example, if you are using IRQ 9, using the following should work.

       LILO: linux ether=9,0,eth0

  Problem: SMC Ultra card is detected as wd8013, but the IRQ and shared
  memory base is wrong.

  Reason: The Ultra card looks a lot like a wd8013, and if the Ultra
  driver is not present in the kernel, the wd driver may mistake the
  ultra as a wd8013. The ultra probe comes before the wd probe, so this
  usually shouldn't happen. The ultra stores the IRQ and mem base in the
  EEPROM differently than a wd8013, hence the bogus values reported.

  Solution: Recompile with only the drivers you need in the kernel. If
  you have a mix of wd and ultra cards in one machine, and are using
  modules, then load the ultra module first.

  3.6.  Problems with 3Com cards

  Problem: The 3c503 picks IRQ N, but this is needed for some other
  device which needs IRQ N. (eg. CD ROM driver, modem, etc.)  Can this
  be fixed without compiling this into the kernel?

  Solution: The 3c503 driver probes for a free IRQ line in the order {5,
  9/2, 3, 4}, and it should pick a line which isn't being used. The
  driver chooses when the card is ifconfig'ed into operation.

  If you are using a modular driver, you can use module parameters to
  set various things, including the IRQ value.

  The following selects IRQ9, base location 0x300, <ignored value>, and
  if_port #1 (the external transceiver).

       io=0x300 irq=9 xcvr=1

  Alternately, if the driver is compiled into the kernel, you can set
  the same values at boot by passing parameters via LILO.

       LILO: linux ether=9,0x300,0,1,eth0

  The following selects IRQ3, probes for the base location, <ignored
  value>, and the default if_port #0 (the internal transceiver)

       LILO: linux ether=3,0,0,0,eth0

  Problem: 3c503: configured interrupt X invalid, will use autoIRQ.

  Reason: The 3c503 card can only use one of IRQ{5, 2/9, 3, 4} (These
  are the only lines that are connected to the card.)  If you pass in an
  IRQ value that is not in the above set, you will get the above
  message.  Usually, specifying an interrupt value for the 3c503 is not
  necessary. The 3c503 will autoIRQ when it gets ifconfig'ed, and pick
  one of IRQ{5, 2/9, 3, 4}.

  Solution: Use one of the valid IRQs listed above, or enable autoIRQ by
  not specifying the IRQ line at all.

  Problem: The supplied 3c503 drivers don't use the AUI (thicknet) port.
  How does one choose it over the default thinnet port?

  Solution: The 3c503 AUI port can be selected at boot-time for in-
  kernel drivers, and at module insertion for modular drivers.  The
  selection is overloaded onto the low bit of the currently-unused
  dev->rmem_start variable, so a boot-time parameter of:

       LILO: linux ether=0,0,0,1,eth0

  should work for in-kernel drivers.

  To specify the AUI port when loading as a module, just append xcvr=1
  to the module options line along with your i/o and irq values.

  3.7.  FAQs Not Specific to Any Card.

  3.7.1.  Ethercard is Not Detected at Boot.

  The usual reason for this is that people are using a kernel that does
  not have support for their particular card built in. For a modular
  kernel, it usually means that the required module has not been
  requested for loading, or that an I/O address needs to be specified as
  a module option.

  If you are using a modular based kernel, such as those installed by
  most of the linux distributions, then try and use the configuration
  utility for the distribution to select the module for your card. For
  ISA cards, it is a good idea to determine the I/O address of the card
  and add it as an option (e.g. io=0x340) if the configuration utility
  asks for any options. If there is no configuration utility, then you
  will have to add the correct module name  (and options) to
  /etc/conf.modules -- see man modprobe for more details.

  If you are using a pre-compiled kernel that is part of a distribution
  set, then check the documentation to see which kernel you installed,
  and if it was built with support for your particular card. If it
  wasn't, then your options are to try and get one that has support for
  your card, or build your own.

  It is usually wise to build your own kernel with only the drivers you
  need, as this cuts down on the kernel size (saving your precious RAM
  for applications!) and reduces the number of device probes that can
  upset sensitive hardware. Building a kernel is not as complicated as
  it sounds. You just have to answer yes or no to a bunch of questions
  about what drivers you want, and it does the rest.

  The next main cause is having another device using part of the i/o
  space that your card needs. Most cards are 16 or 32 bytes wide in i/o
  space. If your card is set at 0x300 and 32 bytes wide, then the driver
  will ask for 0x300-0x31f. If any other device driver has registered
  even one port anywhere in that range, the probe will not take place at
  that address and  the driver will silently continue to the next of the
  probed addresses. So, after booting, do a cat /proc/ioports and verify
  that the full iospace that the card will require is vacant.

  Another problem is having your card jumpered to an i/o address that
  isn't probed by default. There is a list ``probed addresses'' for each
  card in this document. Even if the i/o setting of your card is not in
  the list of porbed addresses, you can supply it at boot (for in-kernel
  drivers) with the ether= command as described in ``Passing Ethernet
  Arguments...''  Modular drivers can make use of the io= option to
  specify an address that isn't probed by default.

  3.7.2.  ifconfig reports the wrong i/o address for the card.

  No it doesn't. You are just interpreting it incorrectly.  This is not
  a bug, and the numbers reported are correct. It just happens that some
  8390 based cards (wd80x3, smc-ultra, etc) have the actual 8390 chip
  living at an offset from the first assigned i/o port.  This is the
  value stored in dev->base_addr, and is what ifconfig reports. If you
  want to see the full range of ports that your card uses, then try cat
  /proc/ioports which will give the numbers you expect.

  3.7.3.  PCI machine detects card but driver fails probe.

  Newer PCI BIOSes may not enable all PCI cards at power-up, especially
  if the BIOS option `PNP OS' is enabled. This mis-feature is to support
  the next release of Windows which still uses some real-mode drivers.
  Either disable this option, or try and upgrade to a newer driver which
  has the code to enable a disabled card.

  3.7.4.  Shared Memory ISA cards in PCI Machine dont work (0xffff)

  This will usually show up as reads of lots of 0xffff values.  No
  shared memory cards of any type will work in a PCI machine unless you
  have the PCI ROM BIOS/CMOS SETUP configuration set properly. You have
  to set it to allow shared memory access from the ISA bus for the
  memory region that your card is trying to use. If you can't figure out
  which settings are applicable then ask your supplier or local computer
  guru. For AMI BIOS, there is usually a "Plug and Play" section where
  there will be an ``ISA Shared Memory Size'' and ``ISA Shared Memory
  Base'' settings. For cards like the wd8013 and SMC Ultra, change the
  size from the default of `Disabled' to 16kB, and change the base to
  the shared memory address of your card.

  3.7.5.  NexGen machine gets `mismatched read page pointers' errors.

  A quirk of the NexGen CPU caused all users with 8390 based cards
  (wd80x3, 3c503, SMC Ultra/EtherEZ, ne2000, etc.) to get these error
  messages. Kernel versions 2.0 and above do not have these problems.
  Upgrade your kernel.

  3.7.6.  Asynchronous Transfer Mode (ATM) Support

  Werner Almesberger has been working on ATM support for linux.  He has
  been working with the Efficient Networks ENI155p board (Efficient
  Networks <http://www.efficient.com/>) and the Zeitnet ZN1221 board
  (Zeitnet <http://www.zeitnet.com/>).

  Werner says that the driver for the ENI155p is rather stable, while
  the driver for the ZN1221 is presently unfinished.

  Check the latest/updated status at the following URL:

  Linux ATM Support <http://lrcwww.epfl.ch/linux-atm/>

  3.7.7.  Gigabyte Ethernet Support

  Is there any gigabyte ethernet support for Linux?

  A driver for the Packet Engines G-NIC PCI Gigabit Ethernet adapter is
  due to be added into the upcoming release of kernel v2.0.34.  For more
  details, support, and driver updates, see:

  http://cesdis.gsfc.nasa.gov/linux/drivers/yellowfin.html

  3.7.8.  FDDI Support

  Is there FDDI support for Linux?

  Yes. Larry Stefani has written a driver for v2.0 with Digital's DEFEA
  (FDDI EISA) and DEFPA (FDDI PCI) cards.  This was included into the
  v2.0.24 kernel.  Currently no other cards are supported though.

  3.7.9.  Full Duplex Support

  Will Full Duplex give me 20MBps? Does Linux support it?

  Cameron Spitzer writes the following about full duplex 10Base-T cards:
  ``If you connect it to a full duplex switched hub, and your system is
  fast enough and not doing much else, it can keep the link busy in both
  directions.  There is no such thing as full duplex 10BASE-2 or
  10BASE-5 (thin and thick coax).  Full Duplex works by disabling
  collision detection in the adapter.  That's why you can't do it with
  coax; the LAN won't run that way.  10BASE-T (RJ45 interface) uses
  separate wires for send and receive, so it's possible to run both ways
  at the same time.  The switching hub takes care of the collision
  problem.  The signalling rate is 10 Mbps.''

  So as you can see, you still will only be able to receive or transmit
  at 10Mbps, and hence don't expect a 2x performance increase. As to
  whether it is supported or not, that depends on the card and possibly
  the driver. Some cards may do auto-negotiation, some may need driver
  support, and some may need the user to select an option in a card's
  EEPROM configuration.  Only the serious/heavy user would notice the
  difference between the two modes anyway.

  3.7.10.  Ethernet Cards for Linux on Alpha/AXP PCI Boards

  As of v2.0, only the 3c509, depca, de4x5 lance32, and all the 8390
  drivers (wd, smc-ultra, ne, 3c503, etc.) have been made `architecture
  independent' so as to work on the DEC Alpha CPU based systems.

  Note that the changes that are required aren't that complicated.  You
  only need to do the following:

  -multiply all jiffies related values by HZ/100 to account for the
  different HZ value that the Alpha uses.  (i.e timeout=2; becomes
  timeout=2*HZ/100;)

  -replace any i/o memory (640k to 1MB) pointer dereferences with the
  appropriate readb() writeb() readl() writel() calls, as shown in this
  example.

  ______________________________________________________________________
  -       int *mem_base = (int *)dev->mem_start;
  -       mem_base[0] = 0xba5eba5e;
  +       unsigned long mem_base = dev->mem_start;
  +       writel(0xba5eba5e, mem_base);
  ______________________________________________________________________

  -replace all memcpy() calls that have i/o memory as source or target
  destinations with the appropriate one of memcpy_fromio() or
  memcpy_toio().

  Details on handling memory accesses in an architecture independent
  fashion are documented in the file linux/Documentation/IO-mapping.txt
  that comes with recent kernels.

  3.7.11.  Linking 10BaseT without a Hub

  Can I link 10BaseT (RJ45) based systems together without a hub?

  You can link 2 machines easily, but no more than that, without extra
  devices/gizmos. See ``Twisted Pair'' -- it explains how to do it. And
  no, you can't hack together a hub just by crossing a few wires and
  stuff. It's pretty much impossible to do the collision signal right
  without duplicating a hub.

  3.7.12.  SIOCSIFxxx: No such device

  I get a bunch of `SIOCSIFxxx: No such device' messages at boot,
  followed by a `SIOCADDRT: Network is unreachable' What is wrong?

  Your ethernet device was not detected at boot/module insertion time,
  and when ifconfig and route are run, they have no device to work with.
  Use dmesg | more to review the boot messages and see if there are any
  messages about detecting an ethernet card.

  3.7.13.  SIOCSFFLAGS: Try again

  I get `SIOCSFFLAGS: Try again' when I run `ifconfig' -- Huh?

  Some other device has taken the IRQ that your ethercard is trying to
  use, and so the ethercard can't use the IRQ.  You don't necessairly
  need to reboot to resolve this, as some devices only grab the IRQs
  when they need them and then release them when they are done. Examples
  are some sound cards, serial ports, floppy disk driver, etc. You can
  type cat /proc/interrupts to see which interrupts are presently in
  use. Most of the Linux ethercard drivers only grab the IRQ when they
  are opened for use via `ifconfig'. If you can get the other device to
  `let go' of the required IRQ line, then you should be able to `Try
  again' with ifconfig.

  3.7.14.  Using `ifconfig' and Link UNSPEC with HW-addr of
  00:00:00:00:00:00

  When I run ifconfig with no arguments, it reports that LINK is UNSPEC
  (instead of 10Mbs Ethernet) and it also says that my hardware address
  is all zeros.

  This is because people are running a newer version of the `ifconfig'
  program than their kernel version. This new version of ifconfig is not
  able to report these properties when used in conjunction with an older
  kernel. You can either upgrade your kernel, `downgrade' ifconfig, or
  simply ignore it. The kernel knows your hardware address, so it really
  doesn't matter if ifconfig can't read it.

  You may also get strange information if the ifconfig program you are
  using is a lot older than the kernel you are using.

  3.7.15.  Huge Number of RX and TX Errors

  When I run ifconfig with no arguments, it reports that I have a huge
  error count in both rec'd and transmitted packets. It all seems to
  work ok -- What is wrong?

  Look again. It says RX packets big number PAUSE errors 0 PAUSE dropped
  0 PAUSE overrun 0.  And the same for the TX column.  Hence the big
  numbers you are seeing are the total number of packets that your
  machine has rec'd and transmitted.  If you still find it confusing,
  try typing cat /proc/net/dev instead.

  3.7.16.  Entries in /dev/ for Ethercards

  I have /dev/eth0 as a link to /dev/xxx. Is this right?

  Contrary to what you have heard, the files in /dev/* are not used.
  You can delete any /dev/wd0, /dev/ne0 and similar entries.

  3.7.17.  Linux and ``trailers''

  Should I disable trailers when I `ifconfig' my ethercard?

  You can't disable trailers, and you shouldn't want to. `Trailers' are
  a hack to avoid data copying in the networking layers. The idea was to
  use a trivial fixed-size header of size `H', put the variable-size
  header info at the end of the packet, and allocate all packets `H'
  bytes before the start of a page. While it was a good idea, it turned
  out to not work well in practice.  If someone suggests the use of
  `-trailers', note that it is the equivalent of sacrificial goats
  blood. It won't do anything to solve the problem, but if problem fixes
  itself then someone can claim deep magical knowledge.

  3.7.18.  Access to the raw Ethernet Device

  How do I get access to the raw ethernet device in linux, without going
  through TCP/IP and friends?

  ______________________________________________________________________
          int s=socket(AF_INET,SOCK_PACKET,htons(ETH_P_ALL));
  ______________________________________________________________________

  This gives you a socket receiving every protocol type.  Do recvfrom()
  calls to it and it will fill the sockaddr with device type in
  sa_family and the device name in the sa_data array. I don't know who
  originally invented SOCK_PACKET for Linux (its been in for ages) but
  its superb stuff.  You can use it to send stuff raw too via sendto()
  calls.  You have to have root access to do either of course.

  4.  Performance Tips

  Here are some tips that you can use if you are suffering from low
  ethernet throughput, or to gain a bit more speed on those ftp
  transfers.

  The ttcp.c program is a good test for measuring raw throughput speed.
  Another common trick is to do a ftp> get large_file /dev/null where
  large_file is > 1MB and residing in the buffer cache on the Tx'ing
  machine. (Do the `get' at least twice, as the first time will be
  priming the buffer cache on the Tx'ing machine.) You want the file in
  the buffer cache because you are not interested in combining the file
  access speed from the disk into your measurement. Which is also why
  you send the incoming data to /dev/null instead of onto the disk.

  4.1.  General Concepts

  Even an 8 bit card is able to receive back-to-back packets without any
  problems. The difficulty arises when the computer doesn't get the Rx'd
  packets off the card quick enough to make room for more incoming
  packets. If the computer does not quickly clear the card's memory of
  the packets already received, the card will have no place to put the
  new packet.

  In this case the card either drops the new packet, or writes over top
  of a previously received packet. Either one seriously interrupts the
  smooth flow of traffic by causing/requesting re-transmissions and can
  seriously degrade performance by up to a factor of 5!

  Cards with more onboard memory are able to ``buffer'' more packets,
  and thus can handle larger bursts of back-to-back packets without
  dropping packets.  This in turn means that the card does not require
  as low a latency from the the host computer with respect to pulling
  the packets out of the buffer to avoid dropping packets.

  Most 8 bit cards have an 8kB buffer, and most 16 bit cards have a 16kB
  buffer. Most Linux drivers will reserve 3kB of that buffer (for two Tx
  buffers), leaving only 5kB of receive space for an 8 bit card. This is
  room enough for only three full sized (1500 bytes) ethernet packets.

  4.2.  ISA Bus Speed

  As mentioned above, if the packets are removed from the card fast
  enough, then a drop/overrun condition won't occur even when the amount
  of Rx packet buffer memory is small. The factor that sets the rate at
  which packets are removed from the card to the computer's memory is
  the speed of the data path that joins the two -- that being the ISA
  bus speed. (If the CPU is a dog-slow 386sx-16, then this will also
  play a role.)

  The recommended ISA bus clock is about 8MHz, but many motherboards and
  peripheral devices can be run at higher frequencies. The clock
  frequency for the ISA bus can usually be set in the CMOS setup, by
  selecting a divisor of the mainboard/CPU clock frequency.

  For example, here are some receive speeds as measured by the TTCP
  program on a 40MHz 486, with an  8 bit WD8003EP card, for different
  ISA bus speeds.

  ______________________________________________________________________
          ISA Bus Speed (MHz)     Rx TTCP (kB/s)
          -------------------     --------------
          6.7                     740
          13.4                    970
          20.0                    1030
          26.7                    1075
  ______________________________________________________________________

  You would be hard pressed to do better than 1075kB/s with any 10Mb/s
  ethernet card, using TCP/IP. However, don't expect every system to
  work at fast ISA bus speeds. Most systems will not function properly
  at speeds above 13MHz. (Also, some PCI systems have the ISA bus speed
  fixed at 8MHz, so that the end user does not have the option of
  increasing it.)

  In addition to faster transfer speeds, one will usually also benefit
  from a reduction in CPU usage due to the shorter duration memory and
  i/o cycles. (Note that hard disks and video cards located on the ISA
  bus will also usually experience a performance increase from an
  increased ISA bus speed.)

  Be sure to back up your data prior to experimenting with ISA bus
  speeds in excess of 8MHz, and thouroughly test that all ISA
  peripherals are operating properly after making any speed increases.

  4.3.  Setting the TCP Rx Window

  Once again, cards with small amounts of onboard RAM and relatively
  slow data paths between the card and the computer's memory run into
  trouble. The default TCP Rx window setting is 32kB, which means that a
  fast computer on the same subnet as you can dump 32k of data on you
  without stopping to see if you received any of it okay.

  Recent versions of the route command have the ability to set the size
  of this window on the fly. Usually it is only for the local net that
  this window must be reduced, as computers that are behind a couple of
  routers or gateways are `buffered' enough to not pose a problem. An
  example usage would be:

  ______________________________________________________________________
          route add <whatever> ... window <win_size>
  ______________________________________________________________________

  where win_size is the size of the window you wish to use (in bytes).
  An 8 bit 3c503 card on an ISA bus operating at a speed of 8MHz or less
  would work well with a window size of about 4kB. Too large a window
  will cause overruns and dropped packets, and a drastic reduction in
  ethernet throughput. You can check the operating status by doing a cat
  /proc/net/dev which will display any dropped or overrun conditions
  that occurred.

  4.4.  Increasing NFS performance

  Some people have found that using 8 bit cards in NFS clients causes
  poorer than expected performance, when using 8kB (native Sun) NFS
  packet size.

  The possible reason for this could be due to the difference in on
  board buffer size between the 8 bit and the 16 bit cards.  The maximum
  ethernet packet size is about 1500 bytes. Now that 8kB NFS packet will
  arrive as about 6 back to back maximum size ethernet packets. Both the
  8 and 16 bit cards have no problem Rx'ing back to back packets. The
  problem arises when the machine doesn't remove the packets from the
  cards buffer in time, and the buffer overflows. The fact that 8 bit
  cards take an extra ISA bus cycle per transfer doesn't help either.
  What you can do if you have an 8 bit card is either set the NFS
  transfer size to 2kB (or even 1kB), or try increasing the ISA bus
  speed in order to get the card's buffer cleared out faster.  I have
  found that an old WD8003E card at 8MHz (with no other system load) can
  keep up with a large receive at 2kB NFS size, but not at 4kB, where
  performance was degraded by a factor of three.

  5.  Vendor/Manufacturer/Model Specific Information

  The following lists many cards in alphabetical order by vendor name
  and then product identifier. Beside each product ID, you will see
  either `Supported', `Semi-Supported' or `Not Supported'.

  Supported means that a driver for that card exists, and many people
  are happily using it and it seems quite reliable.

  Semi-Supported means that a driver exists, but at least one of the
  following descriptions is true: (1) The driver and/or hardware are
  buggy, which may cause poor performance, failing connections or even
  crashes.  (2) The driver is new or the card is fairly uncommon, and
  hence the driver has seen very little use/testing and the driver
  author has had very little feedback. Obviously (2) is preferable to
  (1), and the individual description of the card/driver should make it
  clear which one holds true. In either case, you will probably have to
  answer `Y' when asked ``Prompt for development and/or incomplete
  code/drivers?'' when running make config.

  Not Supported means there is not a driver currently available for that
  card. This could be due to a lack of interest in hardware that is
  rare/uncommon, or because the vendors won't release the hardware
  documentation required to write a driver.

  Note that the difference between `Supported' and `Semi-Supported' is
  rather subjective, and is based on user feedback observed in newsgroup
  postings and mailing list messages. (After all, it is impossible for
  one person to test all drivers with all cards for each kernel
  version!!!) So be warned that you may find a card listed as semi-
  supported works perfectly for you (which is great), or that a card
  listed as supported gives you no end of troubles and problems (which
  is not so great).

  5.1.  3Com

  If you are not sure what your card is, but you think it is a 3Com
  card, you can probably figure it out from the assembly number. 3Com
  has a document `Identifying 3Com Adapters By Assembly Number' (ref
  24500002) that would most likely clear things up. See ``Technical
  Information from 3Com'' for info on how to get documents from 3Com.

  Also note that 3Com has a FTP site with various goodies: ftp.3Com.com
  that you may want to check out.

  For those of you browsing this document by a WWW browser, you can try
  3Com's WWW site as well.

  5.1.1.  3c501

  Status -- Semi-Supported

  Too brain-damaged to use. Available surplus from many places. Avoid it
  like the plague. Again, do not purchase this card, even as a joke.
  It's performance is horrible, and it breaks in many ways.

  For those not yet convinced, the 3c501 can only do one thing at a time
  -- while you are removing one packet from the single-packet buffer it
  cannot receive another packet, nor can it receive a packet while
  loading a transmit packet. This was fine for a network between two
  8088-based computers where processing each packet and replying took
  10's of msecs, but modern networks send back-to-back packets for
  almost every transaction.

  AutoIRQ works, DMA isn't used, the autoprobe only looks at 0x280 and
  0x300, and the debug level is set with the third boot-time argument.

  Once again, the use of a 3c501 is strongly discouraged!  Even more so
  with a IP multicast kernel, as you will grind to a halt while
  listening to all multicast packets. See the comments at the top of the
  source code for more details.

  5.1.2.  3c503, 3c503/16

  Status -- Supported

  If you have a 3c503/16 you may be interested to know that as of 1.3.37
  the driver has the facility to use the full 16kB RAM on your card.
  Previous versions treated the 16bit cards as 8bit cards, and only used
  half of the available RAM. This update also detects the newer 3Com
  prefix found on newly manufactured cards mentioned below.

  Recently made 3c503/16 cards have a new base hardware address because
  3Com ran out of numbers (they made too many cards!) The cards used to
  start with 02 60 8C and the newer ones use 00 20 AF. Up to 1.3.37, the
  driver will only check for the old address, and skip over the newer
  cards.  You can upgrade to a kernel newer than 1.3.37, or change the
  numbers in 3c503.c for older kernels.

  These cards should be about the same speed as the same bus width
  WD80x3, but turn out to be actually a bit slower.  The 3c503 does not
  have ``EEPROM setup'', so a diagnostic/setup program isn't needed
  before running the card with Linux. The shared memory address of the
  3c503 is set using jumpers that are shared with the boot PROM address.
  This is confusing to people familiar with other ISA cards, where you
  always leave the jumper set to ``disable'' unless you have a boot
  PROM.

  These shared-memory ethercards also have a programmed I/O mode that
  doesn't use the 8390 facilities (their engineers found too many bugs!)
  The Linux 3c503 driver can also work with the 3c503 in programmed-I/O
  mode, but this is slower and less reliable than shared memory mode.
  Also, programmed-I/O mode is not as well tested when updating the
  drivers.  You shouldn't use the programmed-I/O mode unless you need it
  for MS-DOS compatibility.

  The 3c503's IRQ line is set in software, with no hints from an EEPROM.
  Unlike the MS-DOS drivers, the Linux driver has capability to autoIRQ:
  it uses the first available IRQ line in {5,2/9,3,4}, selected each
  time the card is ifconfig'ed. (Older driver versions selected the IRQ
  at boot time.) The ioctl() call in `ifconfig' will return EAGAIN if no
  IRQ line is available at that time.

  Some common problems that people have with the 503 are discussed in
  ``Problems with...''.

  If you intend on using this driver as a loadable module you should
  probably see ``Using the Ethernet Drivers as Modules'' and also ``8390
  Based Cards as Modules'' for module specific information.

  5.1.3.  3c505

  Status -- Semi-Supported

  This is a driver that was written by Craig Southeren
  [e-mail]. These cards also use the i82586 chip.
  There are not that many of these cards about.  It is included in the
  standard kernel, but it is classed as an alpha driver. See ``Alpha
  Drivers'' for important information on using alpha-test ethernet
  drivers with Linux.

  There is also the file /usr/src/linux/drivers/net/README.3c505 that
  you should read if you are going to use one of these cards.  It
  contains various options that you can enable/disable.  Technical
  information is available in ``Programming the Intel chips''.

  5.1.4.  3c507

  Status -- Semi-Supported

  This card uses one of the Intel chips, and the development of the
  driver is closely related to the development of the Intel Ether
  Express driver.  The driver is included in the standard kernel
  release, but as an alpha driver.

  See ``Alpha Drivers'' for important information on using alpha-test
  ethernet drivers with Linux. Technical information is available in
  ``Programming the Intel chips''.

  5.1.5.  3c509 / 3c509B

  Status -- Supported

  This card is fairly inexpensive and has good performance for a non-
  bus-master design.  The drawbacks are that the original 3c509 requires
  very low interrupt latency. The 3c509B shouldn't suffer from the same
  problem, due to having a larger buffer. (See below.) These cards use
  PIO transfers, similar to a ne2000 card, and so a shared memory card
  such as a wd8013 will be more efficient in comparison.

  The original 3c509 has a small packet buffer (4kB total, 2kB Rx, 2kB
  Tx), causing the driver to occasionally drop a packet if interrupts
  are masked for too long. To minimize this problem, you can try
  unmasking interrupts during IDE disk transfers (see man hdparm) and/or
  increasing your ISA bus speed so IDE transfers finish sooner.

  The newer model 3c509B has 8kB on board, and the buffer can be split
  4/4, 5/3 or 6/2 for Rx/Tx. This setting is changed with the DOS
  configuration utility, and is stored on the EEPROM. This should
  alleviate the above problem with the original 3c509.

  3c509B users should use the supplied DOS utility to disable the plug
  and play support, and to set the output media to what they require.
  The linux driver currently does not support the Autodetect media
  setting, so you have to select 10Base-T or 10Base-2 or AUI.  With
  regards to the media detection features, Cameron said: ``Autoselect is
  a feature of the commercial drivers for 3C509(B).  AFAIK nobody ever
  claimed the Linux driver attempts it.  When drivers/net/3c509.c
  recognizes my 3C509B at boot time, it says: eth0: 3c509 at 0x300 tag
  1, 10baseT port, ...  revealing that the card is configured for
  10BASE-T.  It finds that out by reading the little EEPROM, which IMHO
  is the Right Way To Do It.''

  As for the plug-and-pray stuff, Cameron adds: ``The 3C509B has 3Com's
  relocatable I/O port scheme, and Microsofttm Plug-and-play ("PnP").
  You can't use them both at the same time.  Some (broken, IMHO) BIOSes
  begin a PnP sequence by writing to the PnP address (0x279 ?), which
  causes PnP adapters like 3C509B to enter the PnP state, but then they
  (these funny BIOSes) never come back to finish the job.  The 3C509Bs
  hang there in the middle of the PnP ID Sequence, where they have no
  idea you didn't mean it and you're going to use the 3Com ID sequence
  after all.  3C5X9CFG /PNPRST clears this hang.  Disable PnP if your
  drivers (eg., Linux) don't use it.

  It was a marketing decision to turn PnP on as a factory default
  setting.  If it caused you a hassle, or not, please take the time to
  say so when you mail in your warranty card.  The more info they have,
  the better decisions they can make.  Also, check with your motherboard
  supplier to see if you need a BIOS upgrade.''

  It has been reported that you have to do a hard reset after doing the
  `3C5X9CFG /PNPRST' for the change to take effect.

  Some people ask about the ``Server or Workstation'' and ``Highest
  Modem Speed'' settings presented in the DOS configuration utility.
  Donald writes ``These are only hints to the drivers, and the Linux
  driver does not use these parameters: it always optimizes for high
  throughput rather than low latency (`Server'). Low latency was
  critically important for old, non-windowed, IPX throughput.  To reduce
  the latency the MS-DOS driver for the 3c509 disables interrupts for
  some operations, blocking serial port interrupts.  Thus the need for
  the `modem speed' setting.  The Linux driver avoids the need to
  disable interrupts for long periods by operating only on whole packets
  e.g. by not starting to transmit a packet until it is completely
  transferred to the card.''

  Note that the ISA card detection uses a different method than most
  cards. Basically, you ask the cards to respond by sending data to an
  ID_PORT (port 0x100).  This detection method means that a particular
  card will always get detected first in a multiple ISA 3c509
  configuration.  The card with the lowest hardware ethernet address
  will always end up being eth0. This shouldn't matter to anyone, except
  for those people who want to assign a 6 byte hardware address to a
  particular interface.  If you have multiple 3c509 cards, it is best to
  append ether=0,0,ethN commands without the i/o port specified (i.e.
  use i/o=zero) and allow the probe to sort out which card is first,
  otherwise it may not detect all your cards.

  If this really bothers you, have a look at Donald's latest driver, as
  you may be able to use a 0x3c509 value in the unused mem address
  fields to order the detection to suit.

  5.1.6.  3c515

  Status -- Not Supported

  This is 3Com's farily recent ISA 100Mbps offering, codenamed
  ``CorkScrew''. Donald is working on support for these cards, and it
  will probably appear in the near future on his WWW driver page. The
  driver will be incorporated into the 3c59x/3c90x driver, so you should
  probably expect to look for it on the Vortex page:

  Vortex <http://cesdis.gsfc.nasa.gov/linux/drivers/vortex.html>

  5.1.7.  3c523

  Status -- Semi-Supported

  This MCA bus card uses the i82586, and  Chris Beauregard has modified
  the ni52 driver to work with these cards. The driver for it can be
  found in the v2.1 kernel source tree.

  More details can be found on the MCA-Linux page at
  http://glycerine.cetmm.uni.edu/mca/

  5.1.8.  3c527

  Status -- Not Supported

  Yes, another MCA card. No, not too much interest in it.  Better
  chances with the 3c529 if you are stuck with MCA.

  5.1.9.  3c529

  Status -- Semi-Supported

  This card actually uses the same chipset as the 3c509.  Donald
  actually put hooks into the 3c509 driver to check for MCA cards after
  probing for EISA cards, and before probing for ISA cards. But it
  hasn't evolved much further than that. Donald writes:

  ``I don't have access to a MCA machine (nor do I fully understand the
  probing code) so I never wrote the mca_adaptor_select_mode() or
  mca_adaptor_id() routines. If you can find a way to get the adaptor
  I/O address that assigned at boot time, you can just hard-wire that in
  place of the commented-out probe. Be sure to keep the code that reads
  the IRQ, if_port, and ethernet address.''

  Darrell Frappier ([e-mail]) reports that you can get
  the i/o address from running the PS/2 reference diskette, and once you
  put that directly into the driver, it does actually work.

  The required MCA probe code will probably appear in the driver in a
  development kernel sometime soon, now that MCA support is in the
  kernel.

  More details can be found on the MCA-Linux page at
  http://glycerine.cetmm.uni.edu/mca/

  5.1.10.  3c562

  Status -- Supported

  This PCMCIA card is the combination of a 3c589B ethernet card with a
  modem. The modem appears as a standard modem to the end user. The only
  difficulty is getting the two separate linux drivers to share one
  interrupt. There are a couple of new registers and some hardware
  interrupt sharing support.  You need to use a v2.0 or newer kernel
  that has the support for interrupt sharing.

  As a side note, the modem part of the card has been reported to be not
  well documented for the end user (the manual just says `supports the
  AT command set') and it may not connect as well as other name brand
  modems. The recommendation is to buy a 3c589B instead, and then get a
  PCMCIA modem card from a company that specializes in modems.

  Thanks again to Cameron for getting a sample unit and documentation
  sent off to David Hinds. Look for support in David's PCMCIA package
  release.

  See ``PCMCIA Support'' for more info on PCMCIA chipsets, socket
  enablers, etc.

  5.1.11.  3c575

  Status -- Not Supported

  A driver for this PCMCIA card is under development and hopefully will
  be included in David's PCMCIA package within a few months.

  5.1.12.  3c579

  Status -- Supported

  The EISA version of the 509. The current EISA version uses the same 16
  bit wide chip rather than a 32 bit interface, so the performance
  increase isn't stunning.  Make sure the card is configured for EISA
  addressing mode.  Read the above 3c509 section for info on the driver.

  5.1.13.  3c589 / 3c589B

  Status -- Semi-Supported

  Many people have been using this PCMCIA card for quite some time now.
  Note that support for it is not (at present) included in the default
  kernel source tree. You will also need a supported PCMCIA controller
  chipset. There are drivers available on Donald's ftp site:

          cesdis.gsfc.nasa.gov:/pub/linux/pcmcia/README.3c589
          cesdis.gsfc.nasa.gov:/pub/linux/pcmcia/3c589.c
          cesdis.gsfc.nasa.gov:/pub/linux/pcmcia/dbether.c

  Or for those that are net-surfing you can try:

  Don's PCMCIA Stuff <http://cesdis.gsfc.nasa.gov/linux/pcmcia.html>

  You will still need a PCMCIA socket enabler as well.

  See ``PCMCIA Support'' for more info on PCMCIA chipsets, socket
  enablers, etc.

  The "B" in the name means the same here as it does for the 3c509 case.

  5.1.14.  3c590 / 3c595

  Status -- Supported

  These ``Vortex'' cards are for PCI bus machines, with the '590 being
  10Mbps and the '595 being 3Com's 100Mbs offering.  Also note that you
  can run the '595 as a '590 (i.e. in a 10Mbps mode).  The driver is
  included in the v2.0 kernel source, but is also continually being
  updated. If you have problems with the driver in the v2.0 kernel, you
  can get an updated driver from the following URL:

  Vortex <http://cesdis.gsfc.nasa.gov/linux/drivers/vortex.html>

  Note that there are two different 3c590 cards out there, early models
  that had 32kB of on-board memory, and later models that only have 8kB
  (eeccch!) of memory. Chances are you won't be able to buy a new 3c59x
  for much longer, as it is being replaced with the 3c90x card. If you
  are buying a used one off somebody, try and get the 32kB version. The
  3c595 cards have 64kB, as you can't get away with only 8kB RAM at
  100Mbps!

  A thanks to Cameron Spitzer and Terry Murphy of 3Com for sending cards
  and documentation to Donald so he could write the driver.

  Donald has set up a mailing list for Vortex driver support.  To join
  the list, just do:

  echo subscribe | /bin/mail [e-mail]

  5.1.15.  3c592 / 3c597

  Status -- Supported

  These are  the EISA versions of the 3c59x series of cards. The
  3c592/3c597 (aka Demon) should work with the vortex driver discussed
  above.

  5.1.16.  3c900 / 3c905

  Status -- Supported

  These cards (aka `Boomerang', aka EtherLink III XL) have been recently
  released to take over the place of the 3c590/3c595 cards.  Cameron
  Spitzer of 3Com writes that the ``3C900 has a scatter gather bus
  master controlled by a descriptor ring in main memory.  Aside from
  that, it's a lot like 3C590.''

  You may still be able to get a couple of these cards at a reduced
  price through one of 3Com's evaluation deals, if you are quick.

  To use this card with v2.0 kernels, you must obtain the updated
  3c59x.c driver from Donald's site at:

  Vortex-Page <http://cesdis.gsfc.nasa.gov/linux/drivers/vortex.html>

  This updated 3c59x driver allows you to use the 3c900 in a 3c59x
  compatible mode, and has been reported to be quite stable. Note that
  this updated driver may be snuck into the v2.0 source tree at a later
  date.)

  On the same WWW page, you will also find the experimental boomerang.c
  driver which uses some of the enhancements of the 3c900 over that
  which is available on the 3c59x cards. Since this is a
  new/experimental driver, you may be better off in using the updated
  3c59x.c if system stability is a primary concern.
  Donald has set up a mailing list for Vortex driver support
  announcements and etc.  To join the list, just do:

  echo subscribe | /bin/mail [e-mail]

  5.2.  Accton

  5.2.1.  Accton MPX

  Status -- Supported

  Don't let the name fool you. This is still supposed to be a NE2000
  compatible card. The MPX is supposed to stand for MultiPacket
  Accelerator, which, according to Accton, increases throughput
  substantially. But if you are already sending back-to-back packets,
  how can you get any faster...

  5.2.2.  Accton EN1203, EN1207, EtherDuo-PCI

  Status -- Supported

  This is another implementation of the DEC 21040 PCI chip.  The EN1207
  card has the 21140, and also has a 10Base-2 connector, which has
  proved troublesome for some people in terms of selecting that media.
  Using the card with 10Base-T and 100Base-T media have worked for
  others though.  So as with all purchases, you should try and make sure
  you can return it if it doesn't work for you.

  See ``DEC 21040'' for more information on these cards, and the present
  driver situation.

  5.2.3.  Accton EN2209 Parallel Port Adaptor (EtherPocket)

  Status -- Semi-Supported

  A driver for these parallel port adapters is available but not yet
  part of the 2.0 or 2.1 kernel source. You have to get the driver from:

  http://www.unix-ag.uni-siegen.de/~nils/accton_linux.html

  5.2.4.  Accton EN2212 PCMCIA Card

  Status -- Semi-Supported

  David Hinds has been working on a driver for this card, and you are
  best to check the latest release of his PCMCIA package to see what the
  present status is.

  5.3.  Allied Telesyn/Telesis

  5.3.1.  AT1500

  Status --Supported

  These are a series of low-cost ethercards using the 79C960 version of
  the AMD LANCE. These are bus-master cards, and hence one of the faster
  ISA bus ethercards available.

  DMA selection and chip numbering information can be found in ``AMD
  LANCE''.

  More technical information on AMD LANCE based Ethernet cards can be
  found in ``Notes on AMD...''.

  5.3.2.  AT1700

  Status -- Supported

  Note that to access this driver during make config you still have to
  answer `Y' when asked ``Prompt for development and/or incomplete
  code/drivers?'' at the first. This is simply due to lack of feedback
  on the driver stability due to it being a relatively rare card.  This
  will probably be changed for v2.1 kernels.

  The Allied Telesis AT1700 series ethercards are based on the Fujitsu
  MB86965. This chip uses a programmed I/O interface, and a pair of
  fixed-size transmit buffers. This allows small groups of packets to be
  sent back-to-back, with a short pause while switching buffers.

  A unique feature is the ability to drive 150ohm STP (Shielded Twisted
  Pair) cable commonly installed for Token Ring, in addition to 10baseT
  100ohm UTP (unshielded twisted pair). A fibre optic version of the
  card (AT1700FT) exists as well.

  The Fujitsu chip used on the AT1700 has a design flaw: it can only be
  fully reset by doing a power cycle of the machine.  Pressing the reset
  button doesn't reset the bus interface. This wouldn't be so bad,
  except that it can only be reliably detected when it has been freshly
  reset. The solution/work-around is to power-cycle the machine if the
  kernel has a problem detecting the AT1700.

  Some production runs of the AT1700 had another problem: they are
  permanently wired to DMA channel 5.  This is undocumented, there are
  no jumpers to disable the "feature", and no driver dares use the DMA
  capability because of compatibility problems. No device driver will be
  written using DMA if installing a second card into the machine breaks
  both, and the only way to disable the DMA is with a knife.

  5.3.3.  AT2450

  Status -- Supported

  This is the PCI version of the AT1500, and it doesn't suffer from the
  problems that the Boca 79c970 PCI card does.  Allied Telsyn was still
  `beta testing' the card in early/mid 1995, so it may not have spread
  to various retailers yet (but it doesn't hurt to ask.)

  DMA selection and chip numbering information can be found in ``AMD
  LANCE''.

  More technical information on AMD LANCE based Ethernet cards can be
  found in ``Notes on AMD...''.

  5.4.  AMD / Advanced Micro Devices

  Carl Ching of AMD was kind enough to provide a very detailed
  description of all the relevant AMD ethernet products which helped
  clear up this section.

  5.4.1.  AMD LANCE (7990, 79C960/961/961A, PCnet-ISA)

  Status -- Supported

  There really is no AMD ethernet card. You are probably reading this
  because the only markings you could find on your card said AMD and the
  above number. The 7990 is the original `LANCE' chip, but most stuff
  (including this document) refer to all these similar chips as `LANCE'
  chips. (...incorrectly, I might add.)

  These above numbers refer to chips from AMD that are the heart of many
  ethernet cards.  For example, the Allied Telesis AT1500 (see
  ``AT1500'') and the NE1500/2100 (see ``NE1500'')  use these chips.

  The 7990/79c90 have long been replaced by newer versions.  The 79C960
  (a.k.a. PCnet-ISA) essentially contains the 79c90 core, along with all
  the other hardware support required, which allows a single-chip
  ethernet solution. The 79c961 (PCnet-ISA+) is a jumperless Plug and
  Play version of the '960. The final chip in the ISA series is the
  79c961A (PCnet-ISA II), which adds full duplex capabilities.  All
  cards with one of these chips should work with the lance.c driver,
  with the exception of very old cards that used the original 7990 in a
  shared memory configuration. These old cards can be spotted by the
  lack of jumpers for a DMA channel.

  One common problem people have is the `busmaster arbitration failure'
  message. This is printed out when the LANCE driver can't get access to
  the bus after a reasonable amount of time has elapsed (50us). This
  usually indicates that the motherboard implementation of bus-mastering
  DMA is broken, or some other device is hogging the bus, or there is a
  DMA channel conflict. If your BIOS setup has the `GAT option' (for
  Guaranteed Access Time) then try toggling/altering that setting to see
  if it helps.

  Also note that the driver only looks at the addresses: 0x300, 0x320,
  0x340, 0x360 for a valid card, and any address supplied by an ether=
  boot argument is silently ignored (this will be fixed) so make sure
  your card is configured for one of the above I/O addresses for now.

  The driver will still work fine, even if more than 16MB of memory is
  installed, since low-memory `bounce-buffers' are used when needed
  (i.e. any data from above 16MB is copied into a buffer below 16MB
  before being given to the card to transmit.)

  The DMA channel can be set with the low bits of the otherwise-unused
  dev->mem_start value (a.k.a. PARAM_1).  (see ``PARAM_1'') If unset it
  is probed for by enabling each free DMA channel in turn and checking
  if initialization succeeds.

  The HP-J2405A board is an exception: with this board it's easy to read
  the EEPROM-set values for the IRQ, and DMA.

  See ``Notes on AMD...''  for more info on these chips.

  5.4.2.  AMD 79C965 (PCnet-32)

  Status -- Supported

  This is the PCnet-32 -- a 32 bit bus-master version of the original
  LANCE chip for VL-bus and local bus systems.  chip.  While these chips
  can be operated with the standard lance.c driver, a 32 bit version
  (lance32.c) is also available that does not have to concern itself
  with any 16MB limitations associated with the ISA bus.

  5.4.3.  AMD 79C970/970A (PCnet-PCI)

  Status -- Supported

  This is the PCnet-PCI -- similar to the PCnet-32, but designed for PCI
  bus based systems. Please see the above PCnet-32 information.  This
  means that you need to build a kernel with PCI BIOS support enabled.
  The '970A adds full duplex support along with some other features to
  the original '970 design.

  Note that the Boca implementation of the 79C970 fails on fast Pentium
  machines. This is a hardware problem, as it affects DOS users as well.
  See the Boca section for more details.

  5.4.4.  AMD 79C971 (PCnet-FAST)

  Status -- Supported

  This is AMD's 100Mbit chip for PCI systems, which also supports full
  duplex operation. It was introduced in June 1996.

  5.4.5.  AMD 79C974 (PCnet-SCSI)

  Status -- Supported

  This is the PCnet-SCSI --  which is basically treated like a '970 from
  an Ethernet point of view.  Also see the above information. Don't ask
  if the SCSI half of the chip is supported -- this is the Ethernet-
  HowTo, not the SCSI-HowTo.

  5.5.  Ansel Communications

  5.5.1.  AC3200 EISA

  Status -- Semi-Supported

  Note that to access this driver during make config you still have to
  answer `Y' when asked ``Prompt for development and/or incomplete
  code/drivers?'' at the first. This is simply due to lack of feedback
  on the driver stability due to it being a relatively rare card.

  This driver is included in the present kernel as an alpha test driver.
  It is based on the common NS8390 chip used in the ne2000 and wd80x3
  cards.  Please see ``Alpha Drivers'' in this document for important
  information regarding alpha drivers.

  If you use it, let one of us know how things work out, as feedback has
  been low, even though the driver has been in the kernel since v1.1.25.

  If you intend on using this driver as a loadable module you should
  probably see ``Using the Ethernet Drivers as Modules'' and also ``8390
  Based Cards as Modules'' for module specific information.

  5.6.  Apricot

  5.6.1.  Apricot Xen-II On Board Ethernet

  Status -- Supported

  This on board ethernet uses an i82596 bus-master chip.  It can only be
  at i/o address 0x300. The author of this driver is Mark Evans. By
  looking at the driver source, it appears that the IRQ is hardwired to
  10.

  Earlier versions of the driver had a tendency to think that anything
  living at 0x300 was an apricot NIC.  Since then the hardware address
  is checked to avoid these false detections.

  5.7.  Arcnet

  Status -- Supported

  With the very low cost and better performance of ethernet, chances are
  that most places will be giving away their Arcnet hardware for free,
  resulting in a lot of home systems with Arcnet.

  An advantage of Arcnet is that all of the cards have identical
  interfaces, so one driver will work for everyone. It also has built in
  error handling so that it supposedly never loses a packet.  (Great for
  UDP traffic!)

  Avery Pennarun's arcnet driver has been in the default kernel sources
  since 1.1.80. The arcnet driver uses `arc0' as its name instead of the
  usual `eth0' for ethernet devices.  Bug reports and success stories
  can be mailed to:

  [e-mail]

  There are information files contained in the standard kernel for
  setting jumpers and general hints.

  Supposedly the driver also works with the 100Mbs ARCnet cards as well!

  5.8.  AT&T

  Note that AT&T's StarLAN is an orphaned technology, like SynOptics
  LattisNet, and can't be used in a standard 10Base-T environment,
  without a hub that `speaks' both.

  5.8.1.  AT&T T7231 (LanPACER+)

  Status -- Not Supported

  These StarLAN cards use an interface similar to the i82586 chip. At
  one point, Matthijs Melchior ([e-mail]) was playing
  with the 3c507 driver, and almost had something useable working.
  Haven't heard much since that.

  5.9.  AT-Lan-Tec / RealTek

  5.9.1.  AT-Lan-Tec / RealTek Pocket adaptor

  Status -- Supported

  This is a generic, low-cost OEM pocket adaptor being sold by AT-Lan-
  Tec, and (likely) a number of other suppliers. A driver for it is
  included in the standard kernel.  Note that there is substantial
  information contained in the driver source file `atp.c'.

  Note that the device name that you pass to ifconfig is not eth0 but
  atp0 for this device.

  5.9.2.  RealTek 8029

  Status -- Supported

  This is a PCI single chip implementation of a NE2000 clone.  Various
  vendors are now selling cards with this chip. See ``NE2000-PCI'' for
  information on using any of these cards.

  5.9.3.  RealTek 8129/8139

  Status -- Semi-Supported

  Another PCI single chip ethernet solution from RealTek.  A driver for
  cards based upon this chip is due to be included in the v2.0.34
  release of linux. For more information, see:

  http://cesdis.gsfc.nasa.gov/linux/drivers/rtl8139.html

  5.10.  Boca Research

  Yes, they make more than just multi-port serial cards.  :-)

  5.10.1.  Boca BEN (PCI, VLB)

  Status -- Supported

  These cards are based on AMD's PCnet chips.  Perspective buyers should
  be warned that many users have had endless problems with these cards.
  Owners of fast Pentium systems have been especially hit. Note that
  this is not a driver problem, as it hits DOS/Win/NT users as well.
  Boca's technical support number is [phone], and you can also
  reach them at [e-mail].

  Donald did a comparitive test with the above Boca PCI card and a
  similar Allied Telsyn PCnet/PCI implementation, which showed that the
  problem lies in Boca's implementation of the PCnet/PCI chip. These
  test results can be accessed on Don's www server.

  Linux at CESDIS <http://cesdis.gsfc.nasa.gov/linux/>

  Boca is offering a `warranty repair' for affected owners, which
  involves adding one of the missing capacitors, but it appears that
  this fix doesn't work 100 percent for most people, although it helps
  some.

  If you are still thinking of buying one of these cards, then at least
  try and get a 7 day unconditional return policy, so that if it doesn't
  work properly in your system, you can return it.

  More general information on the AMD chips can be found in ``AMD
  LANCE''.

  More technical information on AMD LANCE based Ethernet cards can be
  found in ``Notes on AMD...''.

  5.11.  Cabletron

  Donald writes: `Yes, another one of these companies that won't release
  its programming information. They waited for months before actually
  confirming that all their information was proprietary, deliberately
  wasting my time. Avoid their cards like the plague if you can.  Also
  note that some people have phoned Cabletron, and have been told things
  like `a D. Becker is working on a driver for linux' -- making it sound
  like I work for them. This is NOT the case.'

  If you feel like asking them why they don't want to release their low
  level programming info so that people can use their cards, write to
  [e-mail].  Tell them that you are using Linux, and are
  disappointed that they don't support open systems. And no, the usual
  driver development kit they supply is useless. It is just a DOS object
  file that you are supposed to link against. Which you aren't allowed
  to even reverse engineer.

  5.11.1.  E10**, E10**-x, E20**, E20**-x

  Status -- Semi-Supported

  These are NEx000 almost-clones that are reported to work with the
  standard NEx000 drivers, thanks to a ctron-specific check during the
  probe. If there are any problems, they are unlikely to be fixed, as
  the programming information is unavailable.

  5.11.2.  E2100

  Status -- Semi-Supported

  Again, there is not much one can do when the programming information
  is proprietary.  The E2100 is a poor design. Whenever it maps its
  shared memory in during a packet transfer, it maps it into the whole
  128K region! That means you can't safely use another interrupt-driven
  shared memory device in that region, including another E2100.  It will
  work most of the time, but every once in a while it will bite you.
  (Yes, this problem can be avoided by turning off interrupts while
  transferring packets, but that will almost certainly lose clock
  ticks.) Also, if you mis-program the board, or halt the machine at
  just the wrong moment, even the reset button won't bring it back. You
  will have to turn it off and leave it off for about 30 seconds.

  Media selection is automatic, but you can override this with the low
  bits of the dev->mem_end parameter.  See ``PARAM_2''. Module users can
  specify an xcvr=N value on the insmod command line to do the same.

  Also, don't confuse the E2100 for a NE2100 clone.  The E2100 is a
  shared memory NatSemi DP8390 design, roughly similar to a brain-
  damaged WD8013, whereas the NE2100 (and NE1500) use a bus-mastering
  AMD LANCE design.

  There is an E2100 driver included in the standard kernel.  However,
  seeing as programming info isn't available, don't expect bug-fixes.
  Don't use one unless you are already stuck with the card.

  If you intend on using this driver as a loadable module you should
  probably see ``Using the Ethernet Drivers as Modules'' and also ``8390
  Based Cards as Modules'' for module specific information.

  5.11.3.  E22**

  Status -- Semi-Supported

  According to information in a Cabletron Tech Bulletin, these cards use
  the standard AMD PC-Net chipset (see ``AMD PC-Net'') and should work
  with the generic lance driver.

  5.12.  Cogent

  Here is where and how to reach them:

          Cogent Data Technologies, Inc.
          175 West Street, P.O. Box 926
          Friday Harbour, WA 98250, USA.

          Cogent Sales
          15375 S.E. 30th Place, Suite 310
          Bellevue, WA 98007, USA.

          Technical Support:
          Phone [phone] between 8am and 5pm PST
          Fax [phone]
          Compuserve GO COGENT
          Bulletin Board Service [phone]
          Internet: [e-mail]

  5.12.1.  EM100-ISA/EISA

  Status -- Semi-Supported

  These cards use the SMC 91c100 chip and may work with the SMC 91c92
  driver, but this has yet to be verified.

  5.12.2.  Cogent eMASTER+, EM100-PCI, EM400, EM960, EM964

  Status -- Supported

  These are yet another DEC 21040 implementation that should hopefully
  work fine with the standard 21040 driver.

  The EM400 and the EM964 are four port cards using a DEC 21050 bridge
  and 4 21040 chips.

  See ``DEC 21040'' for more information on these cards, and the present
  driver situation.

  5.13.  Compaq

  Compaq aren't really in the business of making ethernet cards, but a
  lot of their systems have embedded ethernet controllers on the
  motherboard.

  5.13.1.  Compaq Deskpro / Compaq XL (Embedded AMD Chip)

  Status -- Supported

  Machines such as the XL series have an AMD 79c97x PCI chip on the
  mainboard that can be used with the standard LANCE driver. But before
  you can use it, you have to do some trickery to get the PCI BIOS to a
  place where Linux can see it. Frank Maas was kind enough to provide
  the details:

  `` The problem with this Compaq machine however is that the PCI
  directory is loaded in high memory, at a spot where the Linux kernel
  can't (won't) reach. Result: the card is never detected nor is it
  usable (sideline: the mouse won't work either) The workaround (as
  described thoroughly in http://www-c724.uibk.ac.at/XL/) is to load MS-
  DOS, launch a little driver Compaq wrote and then load the Linux
  kernel using LOADLIN. Ok, I'll give you time to say `yuck, yuck', but
  for now this is the only working solution I know of. The little driver
  simply moves the PCI directory to a place where it is normally stored
  (and where Linux can find it).''

  More general information on the AMD chips can be found in ``AMD
  LANCE''.

  5.14.  Danpex

  5.14.1.  Danpex EN9400

  Status -- Supported

  Yet another card based on the DEC 21040 chip, reported to work fine,
  and at a relatively cheap price.

  See ``DEC 21040'' for more information on these cards, and the present
  driver situation.

  5.15.  D-Link

  5.15.1.  DE-100, DE-200, DE-220-T, DE-250

  Status -- Supported

  Some of the early D-Link cards didn't have the 0x57 PROM signature,
  but the ne2000 driver knows about them.  For the software configurable
  cards, you can get the config program from www.dlink.com.  The DE2**
  cards were the most widely reported as having the spurious transfer
  address mismatch errors with early versions of linux.  Note that there
  are also cards from Digital (DEC) that are also named DE100 and DE200,
  but the similarity stops there.

  5.15.2.  DE-520

  Status -- Supported

  This is a PCI card using the PCI version of AMD's LANCE chip.  DMA
  selection and chip numbering information can be found in ``AMD
  LANCE''.

  More technical information on AMD LANCE based Ethernet cards can be
  found in ``Notes on AMD...''.

  5.15.3.  DE-530

  Status -- Supported

  This is a generic DEC 21040 PCI chip implementation, and is reported
  to work with the generic 21040 tulip driver.

  See ``DEC 21040'' for more information on these cards, and the present
  driver situation.

  5.15.4.  DE-600

  Status -- Supported

  Laptop users and other folk who might want a quick way to put their
  computer onto the ethernet may want to use this. The driver is
  included with the default kernel source tree.  Bjorn Ekwall
  [e-mail] wrote the driver.  Expect about 180kb/s transfer speed
  from this via the parallel port. You should read the README.DLINK file
  in the kernel source tree.

  Note that the device name that you pass to ifconfig is now eth0 and
  not the previously used dl0.
  If your parallel port is not at the standard 0x378 then you will have
  to recompile. Bjorn writes: ``Since the DE-620 driver tries to sqeeze
  the last microsecond from the loops, I made the irq and port address
  constants instead of variables. This makes for a usable speed, but it
  also means that you can't change these assignements from e.g. lilo;
  you _have_ to recompile...'' Also note that some laptops implement the
  on-board parallel port at 0x3bc which is where the parallel ports on
  monochrome cards were/are.

  5.15.5.  DE-620

  Status -- Supported

  Same as the DE-600, only with two output formats.  Bjorn has written a
  driver for this model, for kernel versions 1.1 and above. See the
  above information on the DE-600.

  5.15.6.  DE-650

  Status -- Semi-Supported

  Some people have been using this PCMCIA card for some time now with
  their notebooks. It is a basic 8390 design, much like a NE2000. The
  LinkSys PCMCIA card and the IC-Card Ethernet (available from Midwest
  Micro) are supposedly DE-650 clones as well.  Note that at present,
  this driver is not part of the standard kernel, and so you will have
  to do some patching.

  See ``PCMCIA Support'' in this document, and if you can, have a look
  at:

  Don's PCMCIA Stuff <http://cesdis.gsfc.nasa.gov/linux/pcmcia.html>

  5.16.  DFI

  5.16.1.  DFINET-300 and DFINET-400

  Status -- Supported

  These cards are now detected (as of 0.99pl15) thanks to Eberhard
  Moenkeberg [e-mail] who noted that they use `DFI' in the first
  3 bytes of the prom, instead of using 0x57 in bytes 14 and 15, which
  is what all the NE1000 and NE2000 cards use. (The 300 is an 8 bit
  pseudo NE1000 clone, and the 400 is a pseudo NE2000 clone.)

  5.17.  Digital / DEC

  5.17.1.  DEPCA, DE100/1, DE200/1/2, DE210, DE422

  Status -- Supported

  As of linux v1.0, there is a driver included as standard for these
  cards. It was written by David C. Davies.  There is documentation
  included in the source file `depca.c', which includes info on how to
  use more than one of these cards in a machine. Note that the DE422 is
  an EISA card. These cards are all based on the AMD LANCE chip.  See
  ``AMD LANCE'' for more info.  A maximum of two of the ISA cards can be
  used, because they can only be set for 0x300 and 0x200 base I/O
  address.  If you are intending to do this, please read the notes in
  the driver source file depca.c in the standard kernel source tree.

  This driver will also work on Alpha CPU based machines, and there are
  various ioctl()s that the user can play with.

  5.17.2.  Digital EtherWorks 3 (DE203, DE204, DE205)

  Status -- Supported

  Included into kernels v1.1.62 and above is this driver, also by David
  C. Davies of DEC. These cards use a proprietary chip from DEC, as
  opposed to the LANCE chip used in the earlier cards like the DE200.
  These cards support both shared memory or programmed I/O, although you
  take about a 50%performance hit if you use PIO mode. The shared memory
  size can be set to 2kB, 32kB or 64kB, but only 2 and 32 have been
  tested with this driver. David says that the performance is virtually
  identical between the 2kB and 32kB mode. There is more information
  (including using the driver as a loadable module) at the top of the
  driver file ewrk3.c and also in README.ewrk3.  Both of these files
  come with the standard kernel distribution.

  The standard driver has a number of interesting ioctl() calls that can
  be used to get or clear packet statistics, read/write the EEPROM,
  change the hardware address, and the like. Hackers can see the source
  code for more info on that one.

  David has also written a configuration utility for this card (along
  the lines of the DOS program NICSETUP.EXE) along with other tools.
  These can be found on sunsite.unc.edu in the directory
  /pub/Linux/system/Network/management -- look for the file ewrk3tools-
  X.XX.tar.gz.

  The next release of this driver (v0.40) will have Alpha CPU support
  like depca.c does and is available from David now if you require it.

  5.17.3.  DE425 (EISA), DE434, DE435, DE500

  Status -- Supported

  These cards are based on the 21040 chip mentioned below.  Included
  into kernels v1.1.86 and above is this driver, also by David C. Davies
  of DEC. It sure is nice to have support from someone on the inside
  ;-) The DE500 uses the newer 21140 chip to provide 10/100Mbs ethernet
  connections.  Have a read of the 21040 section below for extra info.

  Note that as of 1.1.91, David has added a compile time option that
  will allow non-DEC cards to work with this driver. Have a look at
  README.de4x5 for details.

  All the Digital cards will autoprobe for their media (except,
  temporarily, the DE500 due to a patent issue).

  This driver is also ALPHA CPU ready and supports being loaded as a
  module.  Users can access the driver internals through ioctl() calls -
  see the 'ewrk3' tools and the de4x5.c sources for information about
  how to do this.
  5.17.4.  DEC 21040, 21041, 2114x, Tulip

  Status -- Supported

  The DEC 21040 is a bus-mastering single chip ethernet solution from
  Digital, similar to AMD's PCnet chip. The 21040 is specifically
  designed for the PCI bus architecture.  SMC's new EtherPower PCI card
  uses this chip.

  You have a choice of two drivers for cards based on this chip. There
  is the DE425 driver discussed above, and the generic 21040 driver that
  Donald has written.

  Warning: Even though your card may be based upon this chip, the
  drivers may not work for you. David C. Davies writes:

  ``There are no guarantees that either `tulip.c' OR `de4x5.c' will run
  any DC2114x based card other than those they've been written to
  support.  WHY?? You ask.  Because there is a register, the General
  Purpose Register (CSR12) that (1) in the DC21140A is programmable by
  each vendor and they all do it differently (2) in the DC21142/3 this
  is now an SIA control register (a la DC21041). The only small ray of
  hope is that we can decode the SROM to help set up the driver.
  However, this is not a guaranteed solution since some vendors (e.g.
  SMC 9332 card) don't follow the Digital Semiconductor recommended SROM
  programming format."

  In non-technical terms, this means that if you aren't sure that an
  unknown card with a DC2114x chip will work with the linux driver(s),
  then make sure you can return the card to the place of purchase before
  you pay for it.

  The updated 21041 chip is also found in place of the 21040 on most of
  the later SMC EtherPower cards.  The 21140 is for supporting 100Base-?
  and works with the Linux drivers for the 21040 chip.  To use David's
  de4x5 driver with non-DEC cards, have a look at README.de4x5 for
  details.

  Donald has used SMC EtherPower-10/100 cards to develop the `tulip'
  driver. Note that the driver that is in the standard kernel tree at
  the moment is not the most up to date version. If you are having
  trouble with this driver, you should get the newest version from
  Donald's ftp/WWW site.

  Tulip Driver <http://cesdis.gsfc.nasa.gov/linux/drivers/tulip.html>

  The above URL also contains a (non-exhaustive) list of various
  cards/vendors that use the 21040 chip.

  Also note that the tulip driver is still considered an alpha driver
  (see ``Alpha Drivers'') at the moment, and should be treated as such.
  To use it, you will have to edit arch/i386/config.in and uncomment the
  line for CONFIG_DEC_ELCP support.

  Donald has even set up a mailing list for tulip driver support
  announcements, etc.  To join it just type:

  echo subscribe | /bin/mail [e-mail]

  5.18.  Farallon

  Farallon sells EtherWave adaptors and transceivers. This device allows
  multiple 10baseT devices to be daisy-chained.

  5.18.1.  Farallon Etherwave

  Status -- Supported

  This is reported to be a 3c509 clone that includes the EtherWave
  transceiver. People have used these successfully with Linux and the
  present 3c509 driver. They are too expensive for general use, but are
  a great option for special cases.  Hublet prices start at $125, and
  Etherwave adds $75-$100 to the price of the board -- worth it if you
  have pulled one wire too few, but not if you are two network drops
  short.

  5.19.  Hewlett Packard

  The 272** cards use programmed I/O, similar to the NE*000 boards, but
  the data transfer port can be `turned off' when you aren't accessing
  it, avoiding problems with autoprobing drivers.

  Thanks to Glenn Talbott for helping clean up the confusion in this
  section regarding the version numbers of the HP hardware.

  5.19.1.  27245A

  Status -- Supported

  8 Bit 8390 based 10BaseT, not recommended for all the 8 bit reasons.
  It was re-designed a couple years ago to be highly integrated which
  caused some changes in initialization timing which only affected
  testing programs, not LAN drivers. (The new card is not `ready' as
  soon after switching into and out of loopback mode.)

  If you intend on using this driver as a loadable module you should
  probably see ``Using the Ethernet Drivers as Modules'' and also ``8390
  Based Cards as Modules'' for module specific information.

  5.19.2.  HP PC Lan+ (27247, 27252A)

  Status -- Supported

  The HP PC Lan+ is different to the standard HP PC Lan card. This
  driver was added to the list of drivers in the standard kernel during
  the v1.1.x development cycle. It can be operated in either a PIO mode
  like a ne2000, or a shared memory mode like a wd8013.

  The 47B is a 16 Bit 8390 based 10BaseT w/AUI, and the 52A is a 16 Bit
  8390 based ThinLAN w/AUI.  These cards have 32K onboard RAM for Tx/Rx
  packet buffering instead of the usual 16KB, and they both offer LAN
  connector autosense.

  If you intend on using this driver as a loadable module you should
  probably see ``Using the Ethernet Drivers as Modules'' and also ``8390
  Based Cards as Modules'' for module specific information.

  5.19.3.  HP-J2405A

  Status -- Supported

  These are lower priced, and slightly faster than the 27247/27252A, but
  are missing some features, such as AUI, ThinLAN connectivity, and boot
  PROM socket.  This is a fairly generic LANCE design, but a minor
  design decision makes it incompatible with a generic `NE2100' driver.
  Special support for it (including reading the DMA channel from the
  board) is included thanks to information provided by HP's Glenn
  Talbott.

  More technical information on LANCE based cards can be found in
  ``Notes on AMD...''

  5.19.4.  HP-Vectra On Board Ethernet

  Status -- Supported

  The HP-Vectra has an AMD PCnet chip on the motherboard.  Earlier
  kernel versions would detect it as the HP-J2405A but that would fail,
  as the Vectra doesn't report the IRQ and DMA channel like the J2405A.
  Get a kernel newer than v1.1.53 to avoid this problem.

  DMA selection and chip numbering information can be found in ``AMD
  LANCE''.

  More technical information on LANCE based cards can be found in
  ``Notes on AMD...''

  5.19.5.  HP 10/100 VG Any Lan Cards (27248B, J2573, J2577, J2585)

  Status -- Supported

  As of early 1.3.x kernels, this driver was made available by Jaroslav
  Kysela, ([e-mail]). Due to the newness of the driver and the
  relatively small number of VG cards in use, feedback on this driver
  has been low.

  Donald has also written a driver for these cards. Unlike the above, it
  is not presently in the standard kernel source tree.  Check out the
  following URL for more information on Donald's 100VG work.

  Donald's 100VG Page
  <http://cesdis.gsfc.nasa.gov/linux/drivers/100vg.html>

  5.20.  IBM / International Business Machines

  5.20.1.  IBM Thinkpad 300

  Status -- Supported

  This is compatible with the Intel based Zenith Z-note.  See ``Z-note''
  for more info.

  Supposedly this site has a comprehensive database of useful stuff for
  newer versions of the Thinkpad. I haven't checked it out myself yet.

  Thinkpad-info <http://peipa.essex.ac.uk/html/linux-thinkpad.html>

  For those without a WWW browser handy, try
  peipa.essex.ac.uk:/pub/tp750/

  5.20.2.  IBM Credit Card Adaptor for Ethernet

  Status -- Semi-Supported

  People have been using this PCMCIA card with Linux as well.  Similar
  points apply, those being that you need a supported PCMCIA chipset on
  your notebook, and that you will have to patch the PCMCIA support into
  the standard kernel.

  See ``PCMCIA Support'' in this document, and if you can, have a look
  at:

  Don's PCMCIA Stuff <http://cesdis.gsfc.nasa.gov/linux/pcmcia.html>

  5.20.3.  IBM Token Ring

  Status -- Semi-Supported

  To support token ring requires more than only writing a device driver,
  it also requires writing the source routing routines for token ring.
  It is the source routing that would be the most time comsuming to
  write.

  Peter De Schrijver has been spending some time on Token Ring lately.
  and has worked with IBM ISA and MCA token ring cards.

  The present token ring code has been included into the first of the
  1.3.x series kernels.

  Peter says that it was originally tested on an MCA 16/4 Megabit Token
  Ring board, but it should work with other Tropic based boards.

  5.21.  ICL Ethernet Cards

  5.21.1.  ICL EtherTeam 16i/32

  Status -- Supported

  Mika Kuoppala ([e-mail]) wrote this driver, and it was
  included into early 1.3.4x kernels. It uses the Fujitsu MB86965 chip
  that is also used on the at1700 cards.

  5.22.  Intel Ethernet Cards

  5.22.1.  Ether Express

  Status -- Supported

  This card uses the intel i82586. (Surprise, huh?)  Earlier versions of
  this driver (in v1.2 kernels) were classed as alpha-test, as it didn't
  work well for most people.  The driver in the v2.0 kernel seems to
  work much better for those who have tried it. The comments at the top
  of the driver source list some of the problems associated with these
  cards.

  There is also some technical information available on the i82586 in
  ``Programming the Intel Chips'' and also in the source code for the
  driver `eexpress.c'. Don't be afraid to read it. ;-)

  5.22.2.  Ether Express PRO/10

  Status -- Supported

  Bao Chau Ha has written a driver for these cards that has been
  included into early 1.3.x kernels. It may also work with some of the
  Compaq built-in ethernet systems that are based on the i82595 chip.

  5.22.3.  Ether Express PRO/10 PCI (EISA)

  Status -- Semi-Supported

  John Stalba ([e-mail]) has written a driver for the PCI
  version. These cards the PLX9036 PCI interface chip with the Intel
  i82596 LAN controller chip. If your card has the i82557 chip, then you
  don't have this card, but rather the ``+'' version discussed next, and
  hence want the EEPro100 driver instead.

  You can get the alpha driver for the PRO/10 PCI card, along with
  instructions on how to use it at:

  EEPro10 Driver <http://www.ultranet.com/~stalba/eep10pci.html>

  If you have the EISA card, you will probably have to hack the driver a
  bit to account for the different (PCI vs. EISA) detection mechanisms
  that are used in each case.

  5.22.4.  Ether Express PRO/10+

  Status -- Supported

  A slight change in name (from the above) but a different design.  This
  card uses the i82557 chip, and hence uses the eepro100 driver
  described below.

  5.22.5.  Ether Express PRO 10/100B

  Status -- Supported

  A driver for this card is included in the v2.0 kernel source tree, so
  you may no longer have to get it separately.  Note that this driver
  will not work with the older 100A cards.

  For driver updates and/or driver support, have a look at:

  EEPro-100B Page
  <http://cesdis.gsfc.nasa.gov/linux/drivers/eepro100.html>

  Apparently Donald had to sign a non-disclosure agreement that stated
  he could actually disclose the driver source code! How is that for
  sillyness on intel's part?

  This driver will be included into the v2.1 source tree sometime in the
  future. There is also a mailing list for driver announcements. To join
  it, just do:

  echo subscribe | /bin/mail [e-mail]

  5.23.  LinkSys

  LinkSys make a handful of different NE2000 clones, some straight ISA
  cards, some ISA plug and play and some even ne2000-PCI clones based on
  one of the supported ne2000-PCI chipsets. There are just too many
  models to list here.

  Linux gets a mention in their WWW support page. Have a look at:

  http://www.linksys.com/support/solution/nos/linux.htm

  if you are having trouble using one of their cards with linux.

  5.23.1.  LinkSys Etherfast 10/100 Cards.

  Status -- Supported

  Beware with these cards - apparently some use the DEC chipset, and
  some use a proprietary PNIC chipset. The drivers for the DEC chips
  will not work with the PNIC cards. Thanks to Blake Wright for
  reporting this useful bit of information.

  5.23.2.  LinkSys Pocket Ethernet Adapter Plus (PEAEPP)

  Status -- Supported

  This is supposedly a DE-620 clone, and is reported to work well with
  that driver. See ``DE-620'' for more information.

  5.23.3.  LinkSys PCMCIA Adaptor

  Status -- Supported

  This is supposed to be a re-badged DE-650. See ``DE-650'' for more
  information.

  5.24.  Microdyne

  5.24.1.  Microdyne Exos 205T

  Status -- Semi-Supported

  Another i82586 based card. Dirk Niggemann [e-mail] has
  written a driver that he classes as ``pre-alpha'' that he would like
  people to test. Mail him for more details.
  5.25.  Mylex

  Mylex can be reached at the following numbers, in case anyone wants to
  ask them anything.

          MYLEX CORPORATION, Fremont
          Sales:  800-77-MYLEX, [phone]
          FAX:    [phone].

  They also have a web site: Mylex WWW Site <http://www.mylex.com>

  5.25.1.  Mylex LNE390A, LNE390B

  Status -- Semi-Supported

  These are fairly old EISA cards that make use of a shared memory
  implementation similar to the wd80x3. If you are interested in testing
  a driver for this card, contact me (pg).

  5.25.2.  Mylex LNP101

  Status -- Supported

  This is a PCI card that is based on DEC's 21040 chip.  It is
  selectable between 10BaseT, 10Base2 and 10Base5 output.  The LNP101
  card has been verified to work with the generic 21040 driver.

  See the section on the 21040 chip (``DEC 21040'') for more
  information.

  5.25.3.  Mylex LNP104

  Status -- Semi-Supported

  The LNP104 uses the DEC 21050 chip to deliver four independent 10BaseT
  ports. It should work with recent 21040 drivers that know how to share
  IRQs, but nobody has reported trying it yet (that I am aware of).

  5.26.  Novell Ethernet, NExxxx and associated clones.

  The prefix `NE' came from Novell Ethernet. Novell followed the
  cheapest NatSemi databook design and sold the manufacturing rights
  (spun off?) Eagle, just to get reasonably-priced ethercards into the
  market. (The now ubiquitous NE2000 card.)

  5.26.1.  NE1000, NE2000

  Status -- Supported

  NOTE: If you are using a kernel that is older than v1.2.9, it is
  strongly recommended that you upgrade to a newer version. There was an
  important bugfix made to the ne driver in 1.2.7, and another important
  bugfix made to the upper layers (dev.c) in 1.2.9. Both of these bugs
  can cause a ne2000 card to hang your computer.

  The ne2000 is now a generic name for a bare-bones design around the
  NatSemi 8390 chip. They use programmed I/O rather than shared memory,
  leading to easier installation but slightly lower performance and a
  few problems. Again, the savings of using an 8 bit NE1000 over the
  NE2000 are only warranted if you expect light use.  Some problems can
  arise with poor NE2000 clones. You should see ``Problems with...'',
  and ``Poor NE2000 Clones''

  Some recently introduced NE2000 clones use the National Semiconductor
  `AT/LANTic' 83905 chip, which offers a shared memory mode similar to
  the wd8013 and EEPROM software configuration. The shared memory mode
  will offer less CPU usage (i.e. more efficient) than the programmed
  i/o mode.

  In general it is not a good idea to put a NE2000 clone at I/O address
  0x300 because nearly every device driver probes there at boot. Some
  poor NE2000 clones don't take kindly to being prodded in the wrong
  areas, and will respond by locking your machine. Also 0x320 is bad
  because SCSI drivers probe into 0x330.

  Donald has written a NE2000 diagnostic program (ne2k.c) for all ne2000
  cards.  See ``Diagnostic Programs'' for more information.

  If you intend on using this driver as a loadable module you should
  probably see ``Using the Ethernet Drivers as Modules'' and also ``8390
  Based Cards as Modules'' for module specific information.

  5.26.2.  NE2000-PCI (RealTek/Winbond/Compex)

  Status -- Supported

  Yes, believe it or not, people are making PCI cards based on the ten
  year old interface design of the ne2000. At the moment nearly all of
  these cards are based on the RealTek 8029 chip, or the Winbond 89c940
  chip. The Compex, KTI, VIA and Netvin cards apparently also use these
  chips, but have a different PCI ID.  The linux kernel v2.0.33 has
  support to automatically detect all these cards and use them. (If you
  are using a kernel v2.0.30 or older, you should upgrade to ensure your
  card will be detected.)

  Note that you have to say `Y'  to the `Other ISA cards' option when
  running make config as you are actually using the same NE2000 driver
  as the ISA cards use. (That should also give you a hint that these
  cards aren't anywhere as intelligent as say a DEC 21040 card...)  In
  the future, a PCI-only NE2000 driver will be included in the kernel
  source for these cards. The driver is currently available for testing
  at:

  http://cesdis.gsfc.nasa.gov/linux/drivers/ne2k-pci.html

  Some newer motherboards don't enable all the PCI cards at power-up,
  and this generally causes the card to be detected, but to fail the
  probe. Code to enable such cards is due to be added to the v2.0.34
  ne.c driver, based on that which is in the above PCI-only driver.

  If you have a NE2000 PCI card that is not  detected by the driver,
  please contact the maintainer of the NE2000 driver as listed in
  /usr/src/linux/MAINTAINERS along with the output from a cat /proc/pci
  and dmesg so that support for your card can also be added to the
  driver.

  5.26.3.  NE-10/100

  Status -- Not Supported

  These are ISA 100Mbps cards based on the National Semiconductor
  DP83800 and DP83840 chips. There is currently no driver support, nor
  has anyone reported that they are working on a driver.

  5.26.4.  NE1500, NE2100

  Status -- Supported

  These cards use the original 7990 LANCE chip from AMD and are
  supported using the Linux lance driver. Newer NE2100 clones use the
  updated PCnet/ISA chip from AMD.

  Some earlier versions of the lance driver had problems with getting
  the IRQ line via autoIRQ from the original Novell/Eagle 7990 cards.
  Hopefully this is now fixed.  If not, then specify the IRQ via LILO,
  and let us know that it still has problems.

  DMA selection and chip numbering information can be found in ``AMD
  LANCE''.

  More technical information on LANCE based cards can be found in
  ``Notes on AMD...''

  5.26.5.  NE3200

  Status -- Not Supported

  This card uses a lowly 8MHz 80186, and hence you are better off using
  a cheap NE2000 clone. Even if a driver was available, the NE2000 card
  would most likely be faster.

  5.26.6.  NE5500

  Status -- Supported

  These are just AMD PCnet-PCI cards ('970A) chips. More information on
  LANCE/PCnet based cards can be found in ``AMD LANCE''.

  5.27.  Proteon

  5.27.1.  Proteon P1370-EA

  Status -- Supported

  Apparently this is a NE2000 clone, and works fine with Linux.

  5.27.2.  Proteon P1670-EA

  Status -- Supported

  This is yet another PCI card that is based on DEC's Tulip chip.  It
  has been reported to work fine with Linux.

  See the section on the 21040 chip (``DEC 21040'') for more driver
  information.

  5.28.  Pure Data

  5.28.1.  PDUC8028, PDI8023

  Status -- Supported

  The PureData PDUC8028 and PDI8023 series of cards are reported to
  work, thanks to special probe code contributed by Mike Jagdis
  [e-mail]. The support is integrated with the WD
  driver.

  5.29.  Racal-Interlan

  Racal Interlan can be reached via WWW at www.interlan.com. I believe
  they were also known as MiCom-Interlan at one point in the past.

  5.29.1.  ES3210

  Status -- Semi-Supported

  This is an EISA 8390 based shared memory card. An experimetal driver
  for v2.0 is available (from me, pg). It is reported to work fine, but
  the EISA IRQ and shared memory address detection appears not to work
  with (at least) the early revision cards.  In that case, you have to
  supply them at boot; e.g. ether=5,0,0xd0000,eth0 for IRQ 5 and shared
  memory at 0xd0000. The i/o base is automatically detected and hence a
  value of zero should be used.

  This driver will appear in the v2.1 kernels at some time in the near
  future.

  5.29.2.  NI5010

  Status -- Semi-Supported

  This driver, by Jan-Pascal van Best ([e-mail])
  supports the old 8 bit MiCom-Interlan cards. You can get the driver
  from:

  NI5010 Driver
  <http://qv3pluto.leidenuniv.nl/jvbest/ni5010/ni5010.html>

  Jan-Pascal has got very little feedback on this driver and would
  appreciate it if you dropped him a note saying if it worked or not.

  5.29.3.  NI5210

  Status -- Semi-Supported

  Michael Hipp has written a driver for this card. It is included in the
  standard kernel as an `alpha' driver. Michael would like to hear
  feedback from users that have this card. See ``Alpha Drivers'' for
  important information on using alpha-test ethernet drivers with Linux.

  Michael says that ``the internal sysbus seems to be slow.  So we often
  lose packets because of overruns while receiving from a fast remote
  host.''

  This card also uses one of the Intel chips. See ``Programming the
  Intel Chips'' for more technical information.

  5.29.4.  NI6510 (not EB)

  Status -- Semi-Supported

  There is also a driver for the LANCE based NI6510, and it is also
  written by Michael Hipp. Again, it is also an `alpha' driver. For some
  reason, this card is not compatible with the generic LANCE driver. See
  ``Alpha Drivers'' for important information on using alpha-test
  ethernet drivers with Linux.

  5.29.5.  EtherBlaster (aka NI6510EB)

  Status -- Supported

  As of kernel 1.3.23, the generic LANCE driver had a check added to it
  for the 0x52, 0x44 NI6510EB specific signature.  Others have reported
  that this signature is not the same for all NI6510EB cards however,
  which will cause the lance driver to not detect your card. If this
  happens to you, you can change the probe (at about line 322 in
  lance.c) to printk() out what the values are for your card and then
  use them instead of the 0x52, 0x44 defaults.

  The cards should probably be run in `high-performance' mode and not in
  the NI6510 compatible mode when using the lance driver.

  5.30.  Sager

  5.30.1.  Sager NP943

  Status -- Semi-Supported

  This is just a 3c501 clone, with a different S.A. PROM prefix. I
  assume it is equally as brain dead as the original 3c501 as well.
  Kernels 1.1.53 and up check for the NP943 I.D. and then just treat it
  as a 3c501 after that. See ``3Com 3c501'' for all the reasons as to
  why you really don't want to use one of these cards.

  5.31.  Schneider & Koch

  5.31.1.  SK G16

  Status -- Supported

  This driver was included into the v1.1 kernels, and it was written by
  PJD Weichmann and SWS Bern. It appears that the SK G16 is similar to
  the NI6510, in that it is based on the first edition LANCE chip (the
  7990). Once again, it appears as though this card won't work with the
  generic LANCE driver.

  5.32.  SEEQ

  5.32.1.  SEEQ 8005

  Status -- Supported

  This driver was included into early 1.3.x kernels, and was written by
  Hamish Coleman.  There is little information about the card included
  in the driver, and hence little information to be put here. If you
  have a question, you are probably best off e-mailing
  [e-mail]

  5.33.  SMC (Standard Microsystems Corp.)

  Please see ``Western Digital'' for information on SMC cards. (SMC
  bought out Western Digital's network card section quite a while ago.)

  5.34.  Thomas Conrad

  5.34.1.  Thomas Conrad TC-5048

  This is yet another PCI card that is based on DEC's 21040 chip.

  See the section on the 21040 chip (``DEC 21040'') for more
  information.

  5.35.  Western Digital / SMC

  The ethernet part of Western Digital has been bought out by SMC.  One
  common mistake people make is that the relatively new SMC Elite Ultra
  is the same as the older SMC Elite16 models -- this is not the case.
  They have separate drivers.

  Here is how to contact SMC (not that you should need to.)

       SMC / Standard Microsystems Corp., 80 Arkay Drive, Hauppage,
       New York, 11788, USA.

  Technical Support via phone:

          800-992-4762 (USA)
          800-433-5345 (Canada)
          516-435-6250 (Other Countries)

  Literature requests:

          800-SMC-4-YOU (USA)
          800-833-4-SMC (Canada)
          516-435-6255  (Other Countries)

  Technical Support via E-mail:

          [e-mail]

  FTP Site:

          ftp.smc.com

  WWW Site: SMC <http://www.smc.com>

  5.35.1.  WD8003, SMC Elite

  Status -- Supported

  These are the 8-bit versions of the card. The 8 bit 8003 is slightly
  less expensive, but only worth the savings for light use. Note that
  some of the non-EEPROM cards (clones with jumpers, or old old old
  wd8003 cards) have no way of reporting the IRQ line used. In this
  case, auto-irq is used, and if that fails, the driver silently assings
  IRQ 5.  You can get the SMC setup/driver disks from SMC's ftp site.
  Note that some of the newer SMC `SuperDisk' programs will fail to
  detect the real old EEPROM-less cards. The file SMCDSK46.EXE seems to
  be a good all-round choice. Also the jumper settings for all their
  cards are in an ascii text file in the aforementioned archive. The
  latest (greatest?) version can be obtained from ftp.smc.com.

  As these are basically the same as their 16 bit counterparts (WD8013 /
  SMC Elite16), you should see the next section for more information.

  5.35.2.  WD8013, SMC Elite16

  Status -- Supported

  Over the years the design has added more registers and an EEPROM. (The
  first wd8003 cards appeared about ten years ago!)  Clones usually go
  by the `8013' name, and usually use a non-EEPROM (jumpered) design.
  Late model SMC cards will have the SMC 83c690 chip instead of the
  original Nat Semi DP8390 found on earlier cards.  The shared memory
  design makes the cards a bit faster than PIO cards, especially with
  larger packets.  More importantly, from the driver's point of view, it
  avoids a few bugs in the programmed-I/O mode of the 8390, allows safe
  multi-threaded access to the packet buffer, and it doesn't have a
  programmed-I/O data register that hangs your machine during warm-boot
  probes.

  Non-EEPROM cards that can't just read the selected IRQ will attempt
  auto-irq, and if that fails, they will silently assign IRQ 10. (8 bit
  versions will assign IRQ 5)

  Cards with a non standard amount of memory on board can have the
  memory size specified at boot (or at `insmod' time if using modules).
  The standard memory size is 8kB for an 8bit card and 16kB for a 16bit
  card.  For example, the older WD8003EBT cards could be jumpered for
  32kB memory. To make full use of that RAM, you would use something
  like (for i/o=0x280 and IRQ 9):

  ______________________________________________________________________
          LILO: linux ether=9,0x280,0xd0000,0xd8000,eth0
  ______________________________________________________________________

  Also see ``8013 problems'' for some of the more common problems and
  frequently asked questions that pop up often.

  If you intend on using this driver as a loadable module you should
  probably see ``Using the Ethernet Drivers as Modules'' and also ``8390
  Based Cards as Modules'' for module specific information.

  5.35.3.  SMC Elite Ultra

  Status -- Supported

  This ethercard is based on a new chip from SMC, the 83c790, which has
  a few new features. While it has a mode that is similar to the older
  SMC ethercards, it's not entirely compatible with the old WD80*3
  drivers. However, in this mode it shares most of its code with the
  other 8390 drivers, while operating slightly faster than a WD8013
  clone.

  Since part of the Ultra looks like an 8013, the Ultra probe is
  supposed to find an Ultra before the wd8013 probe has a chance to
  mistakenly identify it.

  Donald mentioned that it is possible to write a separate driver for
  the Ultra's `Altego' mode which allows chaining transmits at the cost
  of inefficient use of receive buffers, but that will probably not
  happen.

  Bus-Master SCSI host adaptor users take note: In the manual that ships
  with Interactive UNIX, it mentions that a bug in the SMC Ultra will
  cause data corruption with SCSI disks being run from an aha-154X host
  adaptor.  This will probably bite aha-154X compatible cards, such as
  the BusLogic boards, and the AMI-FastDisk SCSI host adaptors as well.

  SMC has acknowledged the problem occurs with Interactive, and older
  Windows NT drivers. It is a hardware conflict with early revisions of
  the card that can be worked around in the driver design. The current
  Ultra driver protects against this by only enabling the shared memory
  during data transfers with the card. Make sure your kernel version is
  at least 1.1.84, or that the driver version reported at boot is at
  least smc-ultra.c:v1.12 otherwise you are vulnerable.

  If you intend on using this driver as a loadable module you should
  probably see ``Using the Ethernet Drivers as Modules'' and also ``8390
  Based Cards as Modules'' for module specific information.
  5.35.4.  SMC Elite Ultra32 EISA

  Status -- Semi-Supported

  This EISA card shares a lot in common with its ISA counterpart.  A
  working (and stable) driver is available for v2.0 kernels upon request
  from the author of this document. Thanks go to Leonard Zubkoff for
  purchasing some of these cards so that Leonard and myself could add
  linux support for them. The driver will be included with a future
  release of the v2.1.x linux kernel as well.

  5.35.5.  SMC EtherEZ (8416)

  Status -- Supported

  This card uses SMC's 83c795 chip and supports the Plug 'n Play
  specification. It also has an SMC Ultra compatible mode, which allows
  it to be used with the Linux Ultra driver.  Be sure to set your card
  for this compatibility mode.  See the above information for notes on
  the Ultra driver.

  For v1.2 kernels, the card had to be configured for shared memory
  operation. However v2.0 kernels can use the card in shared memory or
  programmed i/o mode. Shared memory mode will be slightly faster, and
  use considerably less CPU resources as well.

  Note that the EtherEZ specific checks were added to the SMC Ultra
  driver in 1.1.84, and hence earlier kernel versions will not detect or
  handle these cards correctly.

  5.35.6.  SMC EtherPower PCI (8432)

  Status -- Supported

  NB: The EtherPower II is an entirely different card. See below!  These
  cards are a basic DEC 21040 implementation, i.e. one big chip and a
  couple of transceivers. Donald has used one of these cards for his
  development of the generic 21040 driver (aka tulip.c). Thanks to Duke
  Kamstra, once again, for supplying a card to do development on.

  Some of the later revisons of this card use the newer DEC 21041 chip,
  which may cause problems with older versions of the tulip driver. If
  you have problems, make sure you are using the latest driver release,
  which may not yet be included in the current kernel source tree.

  See ``DEC 21040'' for more details on using one of these cards, and
  the current status of the driver.

  Apparently, the latest revision of the card, the EtherPower-II uses
  the 9432 chip. It is unclear at the moment if this one will work with
  the present driver. As always, if unsure, check that you can return
  the card if it doesn't work with the linux driver before paying for
  the card.

  5.35.7.  SMC EtherPower II PCI (9432)

  Status -- Semi-Supported

  These cards, based upon the SMC 83c170 chip, are entirely different
  than the Tulip based cards. A new alpha-test driver named epic100.c is
  due to be included in kernel v2.0.34 to support these cards. For more
  details, see:

  http://cesdis.gsfc.nasa.gov/linux/drivers/epic100.html

  5.35.8.  SMC 3008

  Status -- Not Supported

  These 8 bit cards are based on the Fujitsu MB86950, which is an
  ancient version of the MB86965 used in the Linux at1700 driver. Russ
  says that you could probably hack up a driver by looking at the
  at1700.c code and his DOS packet driver for the Tiara card
  (tiara.asm). They are not very common.

  5.35.9.  SMC 3016

  Status -- Not Supported

  These are 16bit i/o mapped 8390 cards, much similar to a generic
  NE2000 card. If you can get the specifications from SMC, then porting
  the NE2000 driver would probably be quite easy.  They are not very
  common.

  5.35.10.  SMC-9000 / SMC 91c92/4

  Status -- Supported

  The SMC9000 is a VLB card based on the 91c92 chip.  The 91c92 appears
  on a few other brand cards as well, but is fairly uncommon.  Erik
  Stahlman ([e-mail]) has written this driver which is in v2.0
  kernels, but not in the older v1.2 kernels. You may be able to drop
  the driver into a v1.2 kernel source tree with minimal difficulty.

  5.35.11.  SMC 91c100

  Status -- Semi-Supported

  The SMC 91c92 driver is supposed to work for cards based on this
  100Base-T chip, but at the moment this is unverified.

  5.36.  Xircom

  For the longest time, Xircom wouldn't release the programming
  information required to write a driver, unless you signed your life
  away. Apparently enough linux users have pestered them for driver
  support (they claim to support all popular networking operating
  systems...) so that they have changed their policy to allow
  documentation to be released without having to sign a non-disclosure
  agreement, and apparently they will release the source code to the SCO
  driver as well.  If you want to verify that this is the case, you can
  reach Xircom at 1-800-874-7875, 1-800-438-4526 or [phone].

  However, at the moment nobody has rushed forth offering to write any
  drivers, so all their products are still unsupported.

  5.36.1.  PE1, PE2, PE3-10B*

  Status -- Not Supported

  Not to get your hopes up, but if you have one of these parallel port
  adaptors, you may be able to use it in the DOS emulator with the
  Xircom-supplied DOS drivers. You will have to allow DOSEMU access to
  your parallel port, and will probably have to play with SIG (DOSEMU's
  Silly Interrupt Generator).

  5.37.  Zenith

  5.37.1.  Z-Note

  Status -- Supported

  The built-in Z-Note network adaptor is based on the Intel i82593 using
  two DMA channels. There is an (alpha?) driver available in the present
  kernel version. As with all notebook and pocket adaptors, it is under
  the `Pocket and portable adaptors' section when running make config.
  See ``Programming the Intel chips'' for more technical information.
  Also note that the IBM ThinkPad 300 is compatible with the Z-Note.

  5.38.  Znyx

  5.38.1.  Znyx ZX342 (DEC 21040 based)

  Status -- Supported

  You have a choice of two drivers for cards based on this chip. There
  is the DE425 driver written by David, and the generic 21040 driver
  that Donald has written.

  Note that as of 1.1.91, David has added a compile time option that may
  allow non-DEC cards (such as the Znyx cards) to work with this driver.
  Have a look at README.de4x5 for details.

  See ``DEC 21040'' for more information on these cards, and the present
  driver situation.

  5.39.  Identifying an Unknown Card

  Okay, so your uncle's cousin's neighbour's friend had a brother who
  found an old ISA ethernet card in the AT case he was using as a cage
  for his son's pet hampster. Somehow you ended up with the card and
  want to try and use it with linux, but nobody has a clue what the card
  is and there isn't any documentation.

  First of all, look for any obvious model numbers that might give a
  clue. Any model number that contains 2000 will most likely be a NE2000
  clone. Any cards with 8003 or 8013 on them somewhere will be
  Western/Digital WD80x3 cards or SMC Elite cards or clones of them.

  5.39.1.  Identifying the Network Interface Controller

  Look for the biggest chip on the card. This will be the network
  controller (NIC) itself, and most can be identified by the part
  number. If you know which NIC is on the card, the following might be
  able to help you figure out what card it is.

  Probably still the most common NIC is the National Semiconductor
  DP8390 aka NS32490 aka DP83901 aka DP83902 aka DP83905 aka DP83907.
  And those are just the ones made by National! Other companies such as
  Winbond and UMC make DP8390 and DP83905 clone parts, such as the
  Winbond 89c904 (DP83905 clone) and the UMC 9090.  If the card has some
  form of 8390 on it, then chances are it is a ne1000 or ne2000 clone
  card. The second most common 8390 based card are wd80x3 cards and
  clones. Cards with a DP83905 can be configured to be an ne2000 or a
  wd8013. Never versions of the genuine wd80x3 and SMC Elite cards have
  an 83c690 in place of the original DP8390. The SMC Ultra cards have an
  83c790, and use a slightly different driver than the wd80x3 cards.
  The SMC EtherEZ cards have an 83c795, and use the same driver as the
  SMC Ultra. All BNC cards based on some sort of 8390 or 8390 clone will
  usually have an 8392 (or 83c692, or XXX392) 16 pin DIP chip very close
  to the BNC connector.

  Another common NIC found on older cards is the Intel i82586.  Cards
  having this NIC include the 3c505, 3c507, 3c523, Intel EtherExpress-
  ISA, Microdyne Exos-205T, and the Racal-Interlan NI5210.

  The original AMD LANCE NIC was numbered AM7990, and newer revisions
  include the 79c960, 79c961, 79c965, 79c970, and 79c974.  Most cards
  with one of the above will work with the Linux LANCE driver, with the
  exception of the old Racal-Interlan NI6510 cards that have their own
  driver.

  Newer PCI cards having a DEC 21040, 21041, 21140, or similar number on
  the NIC should be able to use the linux tulip or de4x5 driver.

  Other PCI cards having a big chip marked RTL8029 are ne2000 clone
  cards, and the ne driver in linux version v2.0 and up should
  automatically detect these cards at boot.

  5.39.2.  Identifying the Ethernet Address

  Each ethernet card has its own six byte address that is unique to that
  card. The first three bytes of that address are the same for each card
  made by that particular manufacturer.  For example all SMC cards start
  with 00:00:c0.  The last three are assigned by the manufacturer
  uniquely to each individual card as they are produced.

  If your card has a sticker on it giving all six bits of its address,
  you can look up the vendor from the first three.  However it is more
  common to see only the last three bytes printed onto a sticker
  attached to a socketed PROM, which tells you nothing.

  You can determine which vendors have which assigned addresses from
  RFC-1340. Apparently there is a more up to date listing available in
  various places as well. Try a WWW or FTP search for EtherNet-codes or
  Ethernet-codes and you will find something.

  5.39.3.  Tips on Trying to Use an Unknown Card

  If you are still not sure what the card is, but have at least narrowed
  it down some, then you can build a kernel with a whole bunch of
  drivers included, and see if any of them autodetect the card at boot.

  If the kernel doesn't detect the card, it may be that the card is not
  configured to one of the addresses that the driver probes when looking
  for a card. In this case, you might want to try getting
  scanport.tar.gz from your local linux ftp site, and see if that can
  locate where your card is jumpered for. It scans ISA i/o space from
  0x100 to 0x3ff looking for devices that aren't registered in
  /proc/ioports. If it finds an unknown device starting at some
  particular address, you can then explicity point the ethernet probes
  at that address with an ether= boot argument.

  If you manage to get the card detected, you can then usually figure
  out the unknown jumpers by changing them one at a time and seeing at
  what i/o base and IRQ that the card is detected at. The IRQ settings
  can also usually be determined by following the traces on the back of
  the card to where the jumpers are soldered through. Counting the `gold
  fingers' on the backside, from the end of the card with the metal
  bracket, you have IRQ 9, 7, 6, 5, 4, 3, 10, 11, 12, 15, 14 at fingers
  4, 21, 22, 23, 24, 25, 34, 35, 36, 37, 38 respectively.  Eight bit
  cards only have up to finger 31.

  Jumpers that appear to do nothing usually are for selecting the memory
  address of an optional boot ROM. Other jumpers that are located near
  the BNC or RJ-45 or AUI connectors are usually to select the output
  media. These are also typically near the `black box' voltage
  converters marked YCL, Valor, or Fil-Mag.

  A nice collection of jumper settings for various cards can be found at
  the following URL: Ethercard Settings
  <http://www.syd.dit.csiro.au/staff/ken/personal/NIC/>

  5.40.  Drivers for Non-Ethernet Devices

  There are a few other drivers that are in the linux source that
  present an ethernet-like device to network programs, while not really
  being ethernet. These are briefly listed here for completeness.

  dummy.c - The purpose of this driver is to provide a device to point a
  route through, but not to actually transmit packets.

  eql.c - Load Equalizer, enslaves multiple devices (usually modems) and
  balances the Tx load across them while presenting a single device to
  the network programs.

  ibmtr.c - IBM Token Ring, which is not really ethernet.  Broken-Ring
  requires source routing and other uglies.

  loopback.c - Loopback device, for which all packets from you machine
  and destined for your own machine go.  It essentially just moves the
  packet off the Tx queue and onto the Rx queue.

  pi2.c - Ottawa Amateur Radio Club PI and PI2 interface.

  plip.c - Parallel Line Internet Protocol, allows two computers to send
  packets to each other over two joined parallel ports in a point-to-
  point fashion.

  ppp.c - Point-to-Point Protocol (RFC1331), for the Transmission of
  Multi-protocol Datagrams over a Point-to-Point Link (again usually
  modems).

  slip.c - Serial Line Internet Protocol, allows two computers to send
  packets to each other over two joined serial ports (usually via
  modems) in a point-to-point fashion.

  tunnel.c - Provides an IP tunnel through which you can tunnel network
  traffic transparently across subnets

  wavelan.c - An Ethernet-like radio transceiver controlled by the Intel
  82586 coprocessor which is used on other ethercards such as the Intel
  EtherExpress.

  6.  Cables, Coax, Twisted Pair

  If you are starting a network from scratch, it's considerably less
  expensive to use thin ethernet, RG58 co-ax cable with BNC connectors,
  than old-fashioned thick ethernet, RG-5 cable with N connectors, or
  10baseT, twisted pair telco-style cables with RJ-45 eight wire `phone'
  connectors. See ``Type of cable...'' for an introductory look at
  cables.

  Also note that the FAQ from comp.dcom.lans.ethernet has a lot of
  useful information on cables and such. Look in Usenet FAQs
  <ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/> for the FAQ for that
  newsgroup.

  6.1.  Thin Ethernet (thinnet)

  Thin ethernet is the `ether of choice'. The cable is inexpensive. If
  you are making your own cables solid-core RG58A is $0.27/m. and
  stranded RG58AU is $0.45/m. Twist-on BNC connectors are < $2 ea., and
  other misc. pieces are similarly inexpensive. It is essential that you
  properly terminate each end of the cable with 50 ohm terminators, so
  budget $2 ea. for a pair. It's also vital that your cable have no
  `stubs' -- the `T' connectors must be attached directly to the
  ethercards.

  The only drawback is that if you have a big loop of machines connected
  together, and some bonehead breaks the loop by taking one cable off
  the side of his tee, the whole network goes down because it sees an
  infinite impedance (open circuit) instead of the required 50 ohm
  termination. Note that you can remove the tee piece from the card
  itself without killing the whole subnet, as long as you don't remove
  the cables from the tee itself. Of course this will disturb the
  machine that you pull the actual tee off of. 8-) And if you are doing
  a small network of two machines, you still need the tees and the 50
  ohm terminators -- you can't just cable them together!

  Note that there are a few cards out there with `on-board termination'.
  These cards have a jumper which when closed, puts a 50 ohm resistor
  across the BNC input. With these cards, you can use a BNC T and
  terminator like normal, or put the cable directly onto the card and
  close the jumper to enable the on-board termination.

  There are also some fancy cable systems which look like a single lead
  going to the card, but the lead is actually a loop, with the two runs
  of cable laying side-by-side covered by an outer sheath, giving the
  lead an oval shaped cross-section. At the turnaround point of the
  loop, a BNC connector is spliced in which connects to your card. So
  you have the equivalent of two runs of cable and a BNC T, but in this
  case, it is impossible for the user to remove a cable from one side of
  the T and disturb the network.

  6.2.  Twisted Pair

  Twisted pair networks require active hubs, which start around $200,
  and the raw cable cost can actually be higher than thinnet. They are
  usually sold using the claim that you can use your existing telephone
  wiring, but it's a rare installation where that turns out to be the
  case. The claim that you can upgrade to higher speeds is also suspect,
  as most proposed schemes use higher-grade (read $$) cable and more
  sophisticated termination ($$$) than you would likely install on
  speculation.

  New gizmos are floating around which allow you to daisy-chain machines
  together, and the like. For example, Farallon sells EtherWave adaptors
  and transceivers. This device allows multiple 10baseT devices to be
  daisy-chained. They also sell a 3c509 clone that includes the
  EtherWave transceiver.  The drawback is that it's more expensive and
  less reliable than a cheap ($100-$150) mini-hub and another ethercard.
  You probably should either go for the hub approach or switch over to
  10base2 thinnet.

  On the other hand, hubs are rapidly dropping in price, all 100Mb/sec
  ethernet proposals use twisted pair, and most new business
  installations use twisted pair. (This is probably to avoid the problem
  with idiots messing with the BNC's as described above.)

  Also, Russ Nelson adds that `New installations should use Category 5
  wiring. Anything else is a waste of your installer's time, as 100Base-
  whatever is going to require Cat 5.'

  If you are only connecting two machines, it is possible to avoid using
  a hub, by swapping the Rx and Tx pairs (1-2 and 3-6).

  If you hold the RJ-45 connector facing you (as if you were going to
  plug it into your mouth) with the lock tab on the top, then the pins
  are numbered 1 to 8 from left to right. The pin usage is as follows:

          Pin Number              Assignment
          ----------              ----------
          1                       Output Data (+)
          2                       Output Data (-)
          3                       Input Data (+)
          4                       Reserved for Telephone use
          5                       Reserved for Telephone use
          6                       Input Data (-)
          7                       Reserved for Telephone use
          8                       Reserved for Telephone use

  If you want to make a cable, the following should spell it out for
  you.  Differential signal pairs must be on the same twisted pair to
  get the required minimal impedance/loss of a UTP cable.  If you look
  at the above table, you will see that 1+2 and 3+6 are the two sets of
  differential signal pairs. Not 1+3 and 2+6 !!!!!!  At 10MHz, with
  short lengths, you *may* get away with such errors, if it is only over
  a short length. Don't even think about it at 100MHz.

  For a normal patch cord, with ends `A' and `B', you want straight
  through pin-to-pin mapping, with the input and output each using a
  pair of twisted wires (for impedance issues). That means 1A goes to
  1B, 2A goes to 2B, 3A goes to 3B and 6A goes to 6B. The wires joining
  1A-1B and 2A-2B must be a twisted pair. Also the wires joining 3A-3B
  and 6A-6B must be another twisted pair.

  Now if you don't have a hub, and want to make a `null cable', what you
  want to do is make the input of `A' be the output of `B' and the
  output of `A' be the input of `B', without changing the polarity.  Tha
  means connecting 1A to 3B (out+ A to in+ B) and 2A to 6B (out- A to
  in- B). These two wires must be a twisted pair. They carry what
  card/plug `A' considers output, and what is seen as input for
  card/plug `B'. Then connect 3A to 1B (in+ A to out+ B) and also
  connect 6A to 2B (in- A to out- B). These second two must also be a
  twisted pair. They carry what card/plug `A' considers input, and what
  card/plug `B' considers output.

  So, if you consider a normal patch cord, chop one end off of it, swap
  the places of the Rx and Tx twisted pairs into the new plug, and crimp
  it down, you then have a `null' cable. Nothing complicated.  You just
  want to feed the Tx signal of one card into the Rx of the second and
  vice versa.

  Note that before 10BaseT was ratified as a standard, there existed
  other network formats using RJ-45 connectors, and the same wiring
  scheme as above. Examples are SynOptics's LattisNet, and AT&T's
  StarLAN.  In some cases, (as with early 3C503 cards) you could set
  jumpers to get the card to talk to hubs of different types, but in
  most cases cards designed for these older types of networks will not
  work with standard 10BaseT networks/hubs. (Note that if the cards also
  have an AUI port, then there is no reason as to why you can't use
  that, combined with an AUI to 10BaseT transceiver.)

  6.3.  Thick Ethernet

  Thick ethernet is mostly obsolete, and is usually used only to remain
  compatible with an existing implementation. You can stretch the rules
  and connect short spans of thick and thin ethernet together with a
  passive $3 N-to-BNC connector, and that's often the best solution to
  expanding an existing thicknet. A correct (but expensive) solution is
  to use a repeater in this case.

  7.  Software Configuration and Card Diagnostics

  In most cases, if the configuration is done by software, and stored in
  an EEPROM, you will usually have to boot DOS, and use the supplied DOS
  program to set the cards IRQ, I/O, mem_addr and whatnot. Besides,
  hopefully it is something you will only be setting once. If you don't
  have the DOS software for your card, try looking on the WWW site of
  your card manufacturer. If you don't know the site name, take a guess
  at it, i.e. `www.my_vendor.com' where `my_vendor' is the name of your
  card manufacturer. This works for SMC, 3Com, and many many other
  manufacturers.

  There are some cards for which Linux versions of the config utils
  exist, and they are listed here.  Donald has written a few small card
  diagnostic programs that run under Linux. Most of these are a result
  of debugging tools that he has created while writing the various
  drivers. Don't expect fancy menu-driven interfaces. You will have to
  read the source code to use most of these. Even if your particular
  card doesn't have a corresponding diagnostic, you can still get some
  information just by typing cat /proc/net/dev -- assuming that your
  card was at least detected at boot.

  In either case, you will have to run most of these programs as root
  (to allow I/O to the ports) and you probably want to shut down the
  ethercard before doing so by typing ifconfig eth0 down (Note: replace
  eth0 with atp0 or whatever when appropriate.)

  7.1.  Configuration Programs for Ethernet Cards

  7.1.1.  WD80x3 Cards

  For people with wd80x3 cards, there is the program wdsetup which can
  be found in wdsetup-0.6a.tar.gz on Linux ftp sites.  I am not sure if
  it is being actively maintained or not, as it has not been updated for
  quite a while. If it works fine for you then great, if not, use the
  DOS version that you should have got with your card. If you don't have
  the DOS version, you will be glad to know that the SMC setup/driver
  disks are available at SMC's ftp site.  Of course, you have to have an
  EEPROM card to use this utility.  Old, old wd8003 cards, and some
  wd8013 clones use jumpers to set up the card instead.

  7.1.2.  Digital / DEC Cards

  The Digital EtherWorks 3 card can be configured in a similar fashion
  to the DOS program NICSETUP.EXE. David C. Davies wrote this and other
  tools for the EtherWorks 3 in conjunction with the driver. Look on
  sunsite.unc.edu in the directory /pub/linux/system/Network/management
  for the file that is named ewrk3tools-X.XX.tar.gz.

  7.1.3.  NE2000+ or AT/LANTIC Cards

  Some Nat Semi DP83905 implementations (such as the AT/LANTIC and the
  NE2000+) are software configurable. (Note that these cards can also
  emulate a wd8013 card!) You can get the file
  /pub/linux/setup/atlantic.c from Donald's ftp server,
  cesdis.gsfc.nasa.gov to configure this card.  In addition, the
  configuration programs for the Kingston DP83905 cards seem to work
  with all cards, as they don't check for a vendor specific address
  before allowing you to use them. Follow the following URL: Kingston
  Software <http://www.kingston.com/download/etherx/etherx.htm> and get
  20XX12.EXE and INFOSET.EXE.

  Be careful when configuring NE2000+ cards, as you can give them bad
  setting values which can cause problems. A typical example is
  accidentally enabling the boot ROM in the EEPROM (even if no ROM is
  installed) to a setting that conflicts with the VGA card. The result
  is a computer that just beeps at you (AMI beep eight times for VGA
  failure) when you turn it on and nothing appears on the screen.

  You can typically recover from this by doing the following: Remove the
  card from the machine, and then boot and enter the CMOS setup.  Change
  the `Display Adapter' to `Not Installed' and change the default boot
  drive to `A:' (your floppy drive).  Also change the `Wait for F1 if
  any Error' to `Disabled'.  This way, the computer should boot without
  user intervention.  Now create a bootable DOS floppy (`format a: /s
  /u') and copy the program default.exe from the 20XX12.EXE archive
  above onto that floppy. Then type echo default > a:autoexec.bat so
  that the program to set the card back to sane defaults will be run
  automatically when you boot from this floppy.  Shut the machine off,
  re-install the ne2000+ card, insert your new boot floppy, and power it
  back up. It will still probably beep at you, but eventually you should
  see the floppy light come on as it boots from the floppy. Wait a
  minute or two for the floppy to stop, indicating that it has finished
  running the default.exe program, and then power down your computer.
  When you then turn it on again, you should hopefully have a working
  display again, allowing you to change your CMOS settings back, and to
  change the card's EEPROM settings back to the values you want.

  Note that if you don't have DOS handy, you can do the whole method
  above with a linux boot disk that automatically runs Donald's atlantic
  program (with the right command line switches) instead of a DOS boot
  disk that automatically runs the default.exe program.

  7.1.4.  3Com Cards

  The 3Com Etherlink III family of cards (i.e. 3c5x9) can be configured
  by using another config utility from Donald.  You can get the file
  /pub/linux/setup/3c5x9setup.c from Donald's ftp server,
  cesdis.gsfc.nasa.gov to configure these cards. (Note that the DOS
  3c5x9B config utility may have more options pertaining to the new
  ``B'' series of the Etherlink III family.)

  7.2.  Diagnostic Programs for Ethernet Cards

  Any of the diagnostic programs that Donald has written can be obtained
  from this URL.

  Ethercard Diagnostics
  <http://cesdis.gsfc.nasa.gov/pub/linux/diag/diagnostic.html>

  Allied Telesis AT1700 -- look for the file /pub/linux/diag/at1700.c on
  cesdis.gsfc.nasa.gov.

  Cabletron E21XX -- look for the file /pub/linux/diag/e21.c on
  cesdis.gsfc.nasa.gov.

  HP PCLAN+ -- look for the file /pub/linux/diag/hp+.c on
  cesdis.gsfc.nasa.gov.

  Intel EtherExpress -- look for the file /pub/linux/diag/eexpress.c on
  cesdis.gsfc.nasa.gov.

  NE2000 cards -- look for the file /pub/linux/diag/ne2k.c on
  cesdis.gsfc.nasa.gov.  There is also a PCI version for the now common
  NE2000-PCI clones.

  RealTek (ATP) Pocket adaptor -- look for the file /pub/linux/diag/atp-
  diag.c on cesdis.gsfc.nasa.gov.

  All Other Cards -- try typing cat /proc/net/dev and dmesg to see what
  useful info the kernel has on the card in question.

  8.  Technical Information

  For those who want to play with the present drivers, or try to make up
  their own driver for a card that is presently unsupported, this
  information should be useful. If you do not fall into this category,
  then perhaps you will want to skip this section.
  8.1.  Probed Addresses

  While trying to determine what ethernet card is there, the following
  addresses are autoprobed, assuming the type and specs of the card have
  not been set in the kernel. The file names below are in
  /usr/src/linux/drivers/net/

  ______________________________________________________________________
          3c501.c         0x280, 0x300
          3c503.c:        0x300, 0x310, 0x330, 0x350, 0x250, 0x280, 0x2a0, 0x2e0
          3c505.c:        0x300, 0x280, 0x310
          3c507.c:        0x300, 0x320, 0x340, 0x280
          3c509.c:        Special ID Port probe
          apricot.c       0x300
          at1700.c:       0x300, 0x280, 0x380, 0x320, 0x340, 0x260, 0x2a0, 0x240
          atp.c:          0x378, 0x278, 0x3bc
          depca.c         0x300, 0x200
          de600.c:        0x378
          de620.c:        0x378
          eexpress.c:     0x300, 0x270, 0x320, 0x340
          hp.c:           0x300, 0x320, 0x340, 0x280, 0x2C0, 0x200, 0x240
          hp-plus.c       0x200, 0x240, 0x280, 0x2C0, 0x300, 0x320, 0x340
          lance.c:        0x300, 0x320, 0x340, 0x360
          ne.c:           0x300, 0x280, 0x320, 0x340, 0x360
          ni52.c          0x300, 0x280, 0x360, 0x320, 0x340
          ni65.c          0x300, 0x320, 0x340, 0x360
          smc-ultra.c:    0x200, 0x220, 0x240, 0x280, 0x300, 0x340, 0x380
          wd.c:           0x300, 0x280, 0x380, 0x240
  ______________________________________________________________________

  There are some NE2000 clone ethercards out there that are waiting
  black holes for autoprobe drivers. While many NE2000 clones are safe
  until they are enabled, some can't be reset to a safe mode.  These
  dangerous ethercards will hang any I/O access to their `dataports'.
  The typical dangerous locations are:

  ______________________________________________________________________
          Ethercard jumpered base     Dangerous locations (base + 0x10 - 0x1f)
                  0x300 *                         0x310-0x317
                  0x320                           0x330-0x337
                  0x340                           0x350-0x357
                  0x360                           0x370-0x377
  ______________________________________________________________________

  * The 0x300 location is the traditional place to put an ethercard, but
  it's also a popular place to put other devices (often SCSI
  controllers). The 0x320 location is often the next one chosen, but
  that's bad for for the AHA1542 driver probe. The 0x360 location is
  bad, because it conflicts with the parallel port at 0x378.  If you
  have two IDE controllers, or two floppy controlers, then 0x360 is also
  a bad choice, as a NE2000 card will clobber them as well.

  Note that kernels > 1.1.7X keep a log of who uses which i/o ports, and
  will not let a driver use i/o ports registered by an earlier driver.
  This may result in probes silently failing.  You can view who is using
  what i/o ports by typing cat /proc/ioports if you have the proc
  filesystem enabled.

  To avoid these lurking ethercards, here are the things you can do:

  ╖  Probe for the device's BIOS in memory space. This is easy and
     always safe, but it only works for cards that always have BIOSes,
     like primary SCSI controllers.

  ╖  Avoid probing any of the above locations until you think you've
     located your device. The NE2000 clones have a reset range from
     <base>+0x18 to <base>+0x1f that will read as 0xff, so probe there
     first if possible. It's also safe to probe in the 8390 space at
     <base>+0x00 - <base>+0x0f, but that area will return quasi-random
     values

  ╖  If you must probe in the dangerous range, for instance if your
     target device has only a few port locations, first check that there
     isn't an NE2000 there. You can see how to do this by looking at the
     probe code in /usr/src/linux/net/inet/ne.c

  ╖  Use the `reserve' boot time argument to protect volatile areas from
     being probed. See the information on using boot time arguments with
     LILO in ``The reserve command''

  8.2.  Writing a Driver

  The only thing that one needs to use an ethernet card with Linux is
  the appropriate driver. For this, it is essential that the
  manufacturer will release the technical programming information to the
  general public without you (or anyone) having to sign your life away.
  A good guide for the likelihood of getting documentation (or, if you
  aren't writing code, the likelihood that someone else will write that
  driver you really, really need) is the availability of the Crynwr (nee
  Clarkson) packet driver. Russ Nelson runs this operation, and has been
  very helpful in supporting the development of drivers for Linux. Net-
  surfers can try this URL to look up Russ' software.

  Russ Nelson's Packet Drivers <http://www.crynwr.com/crynwr/home.html>

  Given the documentation, you can write a driver for your card and use
  it for Linux (at least in theory).  Keep in mind that some old
  hardware that was designed for XT type machines will not function very
  well in a multitasking environment such as Linux. Use of these will
  lead to major problems if your network sees a reasonable amount of
  traffic.

  Most cards come with drivers for MS-DOS interfaces such as NDIS and
  ODI, but these are useless for Linux. Many people have suggested
  directly linking them in or automatic translation, but this is nearly
  impossible. The MS-DOS drivers expect to be in 16 bit mode and hook
  into `software interrupts', both incompatible with the Linux kernel.
  This incompatibility is actually a feature, as some Linux drivers are
  considerably better than their MS-DOS counterparts. The `8390' series
  drivers, for instance, use ping-pong transmit buffers, which are only
  now being introduced in the MS-DOS world.

  (Ping-pong Tx buffers means using at least 2 max-size packet buffers
  for Tx packets. One is loaded while the card is transmitting the
  other. The second is then sent as soon as the first finished, and so
  on. In this way, most cards are able to continuously send back-to-back
  packets onto the wire.)

  OK. So you have decided that you want to write a driver for the Foobar
  Ethernet card, as you have the programming information, and it hasn't
  been done yet. (...these are the two main requirements ;-) You should
  start with the skeleton network driver that is provided with the Linux
  kernel source tree. It can be found in the file
  /usr/src/linux/drivers/net/skeleton.c in all recent kernels.  Also
  have a look at the Kernel Hackers Guide, at the following URL: KHG
  <http://www.redhat.com:8080/HyperNews/get/khg.html>

  8.3.  Driver interface to the kernel

  Here are some notes on the functions that you would have to write if
  creating a new driver. Reading this in conjunction with the above
  skeleton driver may help clear things up.

  8.3.1.  Probe

  Called at boot to check for existence of card. Best if it can check
  un-obtrsively by reading from memory, etc. Can also read from i/o
  ports. Initial writing to i/o ports in a probe is not good as it may
  kill another device.  Some device initialization is usually done here
  (allocating i/o space, IRQs,filling in the dev->??? fields etc.)  You
  need to know what io ports/mem the card can be configured to, how to
  enable shared memory (if used) and how to select/enable interrupt
  generation, etc.

  8.3.2.  Interrupt handler

  Called by the kernel when the card posts an interrupt.  This has the
  job of determining why the card posted an interrupt, and acting
  accordingly. Usual interrupt conditions are data to be rec'd, transmit
  completed, error conditions being reported. You need to know any
  relevant interrupt status bits so that you can act accordingly.

  8.3.3.  Transmit function

  Linked to dev->hard_start_xmit() and is called by the kernel when
  there is some data that the kernel wants to put out over the device.
  This puts the data onto the card and triggers the transmit. You need
  to know how to bundle the data and how to get it onto the card (shared
  memory copy, PIO transfer, DMA?) and in the right place on the card.
  Then you need to know how to tell the card to send the data down the
  wire, and (possibly) post an interrupt when done.  When the hardware
  can't accept additional packets it should set the dev->tbusy flag.
  When additional room is available, usually during a transmit-complete
  interrupt, dev->tbusy should be cleared and the higher levels informed
  with mark_bh(INET_BH).

  8.3.4.  Receive function

  Called by the kernel interrupt handler when the card reports that
  there is data on the card. It pulls the data off the card, packages it
  into a sk_buff and lets the kernel know the data is there for it by
  doing a netif_rx(sk_buff). You need to know how to enable interrupt
  generation upon Rx of data, how to check any relevant Rx status bits,
  and how to get that data off the card (again sh mem, PIO, DMA, etc.)

  8.3.5.  Open function

  linked to dev->open and called by the networking layers when somebody
  does ifconfig eth0 up - this puts the device on line and enables it
  for Rx/Tx of data. Any special initialization incantations that were
  not done in the probe sequence (enabling IRQ generation, etc.)  would
  go in here.

  8.3.6.  Close function (optional)

  This puts the card in a sane state when someone does ifconfig eth0
  down.  It should free the IRQs and DMA channels if the hardware
  permits, and turn off anything that will save power (like the
  transceiver).

  8.3.7.  Miscellaneous functions

  Things like a reset function, so that if things go south, the driver
  can try resetting the card as a last ditch effort.  Usually done when
  a Tx times out or similar. Also a function to read the statistics
  registers of the card if so equipped.

  8.4.  Interrupts and Linux

  There are two kinds of interrupt handlers in Linux: fast ones and slow
  ones. You decide what kind you are installing by the flags you pass to
  irqaction(). The fast ones, such as the serial interrupt handler, run
  with _all_ interrupts disabled. The normal interrupt handlers, such as
  the one for ethercard drivers, runs with other interrupts enabled.

  There is a two-level interrupt structure. The `fast' part handles the
  device register, removes the packets, and perhaps sets a flag.  After
  it is done, and interrupts are re-enabled, the slow part is run if the
  flag is set.

  The flag between the two parts is set by:

       mark_bh(INET_BH);

  Usually this flag is set within dev_rint() during a received-packet
  interrupt, and set directly by the device driver during a transmit-
  complete interrupt.

  You might wonder why all interrupt handlers cannot run in `normal
  mode' with other interrupts enabled. Ross Biro uses this scenario to
  illustrate the problem:

  ╖  You get a serial interrupt, and start processing it.  The serial
     interrupt is now masked.

  ╖  You get a network interrupt, and you start transferring a maximum-
     sized 1500 byte packet from the card.

  ╖  Another character comes in, but this time the interrupts are
     masked!

  The `fast' interrupt structure solves this problem by allowing
  bounded-time interrupt handlers to run without the risk of leaving
  their interrupt lines masked by another interrupt request.

  There is an additional distinction between fast and slow interrupt
  handlers -- the arguments passed to the handler. A `slow' handler is
  defined as

  ______________________________________________________________________

                  static void
                  handle_interrupt(int reg_ptr)
                  {
                      int irq = -(((struct pt_regs *)reg_ptr)->orig_eax+2);
                      struct device *dev = irq2dev_map[irq];
                  ...
  ______________________________________________________________________

  While a fast handler gets the interrupt number directly

  ______________________________________________________________________

                  static void
                  handle_fast_interrupt(int irq)
                  {
                  ...
  ______________________________________________________________________

  A final aspect of network performance is latency. The only board that
  really addresses this is the 3c509, which allows a predictive
  interrupt to be posted. It provides an interrupt response timer so
  that the driver can fine-tune how early an interrupt is generated.

  8.5.  Programming the Intel chips (i82586 and i82593)

  These chips are used on a number of cards, namely the 3c507 ('86), the
  Intel EtherExpress 16 ('86), Microdyne's exos205t ('86), the Z-Note
  ('93), and the Racal-Interlan ni5210 ('86).

  Russ Nelson writes: `Most boards based on the 82586 can reuse quite a
  bit of their code.  More, in fact, than the 8390-based adapters. There
  are only three differences between them:

  ╖  The code to get the Ethernet address,

  ╖  The code to trigger CA on the 82586, and

  ╖  The code to reset the 82586.

  The Intel EtherExpress 16 is an exception, as it I/O maps the 82586.
  Yes, I/O maps it. Fairly clunky, but it works.

  Garrett Wollman did an AT&T driver for BSD that uses the BSD
  copyright. The latest version I have (Sep '92) only uses a single
  transmit buffer. You can and should do better than this if you've got
  the memory. The AT&T and 3c507 adapters do; the ni5210 doesn't.

  The people at Intel gave me a very big clue on how you queue up
  multiple transmit packets. You set up a list of NOP-> XMIT-> NOP->
  XMIT-> NOP-> XMIT-> beginning) blocks, then you set the `next' pointer
  of all the NOP blocks to themselves. Now you start the command unit on
  this chain. It continually processes the first NOP block. To transmit
  a packet, you stuff it into the next transmit block, then point the
  NOP to it. To transmit the next packet, you stuff the next transmit
  block and point the previous NOP to it. In this way, you don't have to
  wait for the previous transmit to finish, you can queue up multiple
  packets without any ambiguity as to whether it got accepted, and you
  can avoid the command unit start-up delay.'

  8.6.  Technical information from 3Com

  If you are interested in working on drivers for 3Com cards, you can
  get technical documentation from 3Com. Cameron has been kind enough to
  tell us how to go about it below:

  3Com's Ethernet Adapters are documented for driver writers in our
  `Technical References' (TRs). These manuals describe the programmer
  interfaces to the boards but they don't talk about the diagnostics,
  installation programs, etc that end users can see.

  The Network Adapter Division marketing department has the TRs to give
  away. To keep this program efficient, we centralized it in a thing
  called `CardFacts.' CardFacts is an automated phone system. You call
  it with a touch-tone phone and it faxes you stuff. To get a TR, call
  CardFacts at 408-727-7021. Ask it for Developer's Order Form, document
  number 9070. Have your fax number ready when you call. Fill out the
  order form and fax it to 408-764-5004.  Manuals are shipped by Federal
  Express 2nd Day Service.

  After you get a manual, if you still can't figure out how to program
  the board, try our `CardBoard' BBS at 1-800-876-3266, and if you can't
  do that, write [e-mail] and ask him for alternatives.
  If you have a real stumper that nobody has figured out yet, the fellow
  who needs to know about it is [e-mail].

  There are people here who think we are too free with the manuals, and
  they are looking for evidence that the system is too expensive, or
  takes too much time and effort. That's why it's important to try to
  use CardFacts before you start calling and mailing the people I named
  here.

  There are even people who think we should be like Diamond and Xircom,
  requiring tight `partnership' with driver writers to prevent poorly
  performing drivers from getting written. So far, 3Com customers have
  been really good about this, and there's no problem with the level of
  requests we've been getting. We need your continued cooperation and
  restraint to keep it that way.

          Cameron Spitzer, 408-764-6339
          3Com NAD
          Santa Clara
          work: [e-mail]
          home: [e-mail]

  8.7.  Notes on AMD PCnet / LANCE Based cards

  The AMD LANCE (Local Area Network Controller for Ethernet) was the
  original offering, and has since been replaced by the `PCnet-ISA'
  chip, otherwise known as the 79C960.  A relatively new chip from AMD,
  the 79C960, is the heart of many new cards being released at present.
  Note that the name `LANCE' has stuck, and some people will refer to
  the new chip by the old name. Dave Roberts of the Network Products
  Division of AMD was kind enough to contribute the following
  information regarding this chip:

  `As for the architecture itself, AMD developed it originally and
  reduced it to a single chip -- the PCnet(tm)-ISA -- over a year ago.
  It's been selling like hotcakes ever since.

  Functionally, it is equivalent to a NE1500. The register set is
  identical to the old LANCE with the 1500/2100 architecture additions.
  Older 1500/2100 drivers will work on the PCnet-ISA.  The NE1500 and
  NE2100 architecture is basically the same.  Initially Novell called it
  the 2100, but then tried to distinguish between coax and 10BASE-T
  cards. Anything that was 10BASE-T only was to be numbered in the 1500
  range. That's the only difference.

  Many companies offer PCnet-ISA based products, including HP, Racal-
  Datacom, Allied Telesis, Boca Research, Kingston Technology, etc.  The
  cards are basically the same except that some manufacturers have added
  `jumperless' features that allow the card to be configured in
  software. Most have not. AMD offers a standard design package for a
  card that uses the PCnet-ISA and many manufacturers use our design
  without change.  What this means is that anybody who wants to write
  drivers for most PCnet-ISA based cards can just get the data-sheet
  from AMD. Call our literature distribution center at [phone] and
  ask for the Am79C960, PCnet-ISA data sheet. It's free.

  A quick way to understand whether the card is a `stock' card is to
  just look at it. If it's stock, it should just have one large chip on
  it, a crystal, a small IEEE address PROM, possibly a socket for a boot
  ROM, and a connector (1, 2, or 3, depending on the media options
  offered). Note that if it's a coax card, it will have some transceiver
  stuff built onto it as well, but that should be near the connector and
  away from the PCnet-ISA.'

  There is also some info regarding the LANCE chip in the file lance.c
  which is included in the standard kernel.

  A note to would-be card hackers is that different LANCE
  implementations do `restart' in different ways. Some pick up where
  they left off in the ring, and others start right from the beginning
  of the ring, as if just initialised. This is a concern when setting
  the multicast list.

  8.8.  Multicast and Promiscuous Mode

  Another one of the things Donald has worked on is implementing
  multicast and promiscuous mode hooks.  All of the released (i.e. not
  ALPHA) ISA drivers now support promiscuous mode.

  Donald writes: `At first I was planning to do it while implementing
  either the /dev/* or DDI interface, but that's not really the correct
  way to do it. We should only enable multicast or promiscuous modes
  when something wants to look at the packets, and shut it down when
  that application is finished, neither of which is strongly related to
  when the hardware is opened or released.
  I'll start by discussing promiscuous mode, which is conceptually easy
  to implement. For most hardware you only have to set a register bit,
  and from then on you get every packet on the wire. Well, it's almost
  that easy; for some hardware you have to shut the board (potentially
  dropping a few packet), reconfigure it, and then re-enable the
  ethercard. This is grungy and risky, but the alternative seems to be
  to have every application register before you open the ethercard at
  boot-time.

  OK, so that's easy, so I'll move on something that's not quite so
  obvious: Multicast. It can be done two ways:

  1. Use promiscuous mode, and a packet filter like the Berkeley packet
     filter (BPF). The BPF is a pattern matching stack language, where
     you write a program that picks out the addresses you are interested
     in. Its advantage is that it's very general and programmable. Its
     disadvantage is that there is no general way for the kernel to
     avoid turning on promiscuous mode and running every packet on the
     wire through every registered packet filter. See ``The Berkeley
     Packet Filter'' for more info.

  2. Using the built-in multicast filter that most etherchips have.

  I guess I should list what a few ethercards/chips provide:

          Chip/card  Promiscuous  Multicast filter
          ----------------------------------------
          Seeq8001/3c501  Yes     Binary filter (1)
          3Com/3c509      Yes     Binary filter (1)
          8390            Yes     Autodin II six bit hash (2) (3)
          LANCE           Yes     Autodin II six bit hash (2) (3)
          i82586          Yes     Hidden Autodin II six bit hash (2) (4)

  1. These cards claim to have a filter, but it's a simple yes/no
     `accept all multicast packets', or `accept no multicast packets'.

  2. AUTODIN II is the standard ethernet CRC (checksum) polynomial. In
     this scheme multicast addresses are hashed and looked up in a hash
     table. If the corresponding bit is enabled, this packet is
     accepted. Ethernet packets are laid out so that the hardware to do
     this is trivial -- you just latch six (usually) bits from the CRC
     circuit (needed anyway for error checking) after the first six
     octets (the destination address), and use them as an index into the
     hash table (six bits -- a 64-bit table).

  3. These chips use the six bit hash, and must have the table computed
     and loaded by the host. This means the kernel must include the CRC
     code.

  4. The 82586 uses the six bit hash internally, but it computes the
     hash table itself from a list of multicast addresses to accept.

  Note that none of these chips do perfect filtering, and we still need
  a middle-level module to do the final filtering. Also note that in
  every case we must keep a complete list of accepted multicast
  addresses to recompute the hash table when it changes.
  My first pass at device-level support is detailed in the outline
  driver skeleton.c

  It looks like the following:

  ______________________________________________________________________
          #ifdef HAVE_MULTICAST
          static void set_multicast_list(struct device *dev, int num_addrs,
                           void *addrs);
          #endif
          .
          .

          ethercard_open() {
          ...
          #ifdef HAVE_MULTICAST
                  dev->set_multicast_list = &set_multicast_list;
          #endif
          ...

          #ifdef HAVE_MULTICAST
          /* Set or clear the multicast filter for this adaptor.
             num_addrs -- -1      Promiscuous mode, receive all packets
             num_addrs -- 0       Normal mode, clear multicast list
             num_addrs > 0        Multicast mode, receive normal and
                  MC packets, and do best-effort filtering.
           */
          static void
          set_multicast_list(struct device *dev, int num_addrs, void *addrs)
          {
          ...
  ______________________________________________________________________

  Any comments, criticism, etc. are welcome.'

  8.9.  The Berkeley Packet Filter (BPF)

  The general idea of the developers is that the BPF functionality
  should not be provided by the kernel, but should be in a (hopefully
  little-used) compatibility library.

  For those not in the know: BPF (the Berkeley Packet Filter) is an
  mechanism for specifying to the kernel networking layers what packets
  you are interested in. It's implemented as a specialized stack
  language interpreter built into a low level of the networking code. An
  application passes a program written in this language to the kernel,
  and the kernel runs the program on each incoming packet. If the kernel
  has multiple BPF applications, each program is run on each packet.

  The problem is that it's difficult to deduce what kind of packets the
  application is really interested in from the packet filter program, so
  the general solution is to always run the filter. Imagine a program
  that registers a BPF program to pick up a low data-rate stream sent to
  a multicast address.  Most ethernet cards have a hardware multicast
  address filter implemented as a 64 entry hash table that ignores most
  unwanted multicast packets, so the capability exists to make this a
  very inexpensive operation. But with the BFP the kernel must switch
  the interface to promiscuous mode, receive _all_ packets, and run them
  through this filter. This is work, BTW, that's very difficult to
  account back to the process requesting the packets.

  9.  Networking with a Laptop/Notebook Computer

  There are currently only a few ways to put your laptop on a network.
  You can use the SLIP code (and run at serial line speeds); you can buy
  one of the few laptops that come with a NE2000-compatible ethercard;
  you can get a notebook with a supported PCMCIA slot built-in; you can
  get a laptop with a docking station and plug in an ISA ethercard; or
  you can use a parallel port Ethernet adapter such as the D-Link
  DE-600.

  9.1.  Using SLIP

  This is the cheapest solution, but by far the most difficult. Also,
  you will not get very high transmission rates. Since SLIP is not
  really related to ethernet cards, it will not be discussed further
  here. See the NET-2 Howto.

  9.2.  Built in NE2000

  This solution severely limits your laptop choices and is fairly
  expensive. Be sure to read the specifications carefully, as you may
  find that you will have to buy an additional non-standard transceiver
  to actually put the machine on a network. A good idea might be to boot
  the notebook with a kernel that has ne2000 support, and make sure it
  gets detected and works before you lay down your cash.

  9.3.  PCMCIA Support

  As this area of Linux development is fairly young, I'd suggest that
  you join the LAPTOPS mailing channel. See ``Mailing lists...''  which
  describes how to join a mailing list channel.

  Try and determine exactly what hardware you have (ie. card
  manufacturer, PCMCIA chip controller manufacturer) and then ask on the
  LAPTOPS channel. Regardless, don't expect things to be all that
  simple.  Expect to have to fiddle around a bit, and patch kernels,
  etc.  Maybe someday you will be able to type `make config' 8-)

  At present, the two PCMCIA chipsets that are supported are the
  Databook TCIC/2 and the intel i82365.

  There is a number of programs on tsx-11.mit.edu in
  /pub/linux/packages/laptops/ that you may find useful. These range
  from PCMCIA Ethercard drivers to programs that communicate with the
  PCMCIA controller chip. Note that these drivers are usually tied to a
  specific PCMCIA chip (ie. the intel 82365 or the TCIC/2)

  For NE2000 compatible cards, some people have had success with just
  configuring the card under DOS, and then booting linux from the DOS
  command prompt via loadlin.

  For those that are net-surfing you can try:

  Don's PCMCIA Stuff <http://cesdis.gsfc.nasa.gov/linux/pcmcia.html>

  Anyway, the PCMCIA driver problem isn't specific to the Linux world.
  It's been a real disaster in the MS-DOS world. In that world people
  expect the hardware to work if they just follow the manual.  They
  might not expect it to interoperate with any other hardware or
  software, or operate optimally, but they do expect that the software
  shipped with the product will function. Many PCMCIA adaptors don't
  even pass this test.

  Things are looking up for Linux users that want PCMCIA support, as
  substantial progress is being made. Pioneering this effort is David
  Hinds. His latest PCMCIA support package can be obtained from cb-
  iris.stanford.edu in the directory /pub/pcmcia/. Look for a file like
  pcmcia-cs-X.Y.Z.tgz where X.Y.Z will be the latest version number.
  This is most likely uploaded to tsx-11.mit.edu as well.

  Note that Donald's PCMCIA enabler works as a user-level process, and
  David Hinds' is a kernel-level solution.  You may be best served by
  David's package as it is much more widely used.

  9.4.  ISA Ethercard in the Docking Station.

  Docking stations for laptops typically cost about $250 and provide two
  full-size ISA slots, two serial and one parallel port. Most docking
  stations are powered off of the laptop's batteries, and a few allow
  adding extra batteries in the docking station if you use short ISA
  cards. You can add an inexpensive ethercard and enjoy full-speed
  ethernet performance.

  9.5.  Pocket / parallel port adaptors.

  The `pocket' ethernet adaptors may also fit your need.  Until recently
  they actually costed more than a docking station and cheap ethercard,
  and most tie you down with a wall-brick power supply.  At present, you
  can choose from the D-Link, or the RealTek adaptor.  Most other
  companies treat the programming information as a trade secret, so
  support will likely be slow in coming. (if ever!)  Xircom (see
  ``Xircom'') apparently are now releasing their specs, but nobody is
  currently working on a driver.

  Note that the transfer speed will not be all that great (perhaps
  200kB/s tops?) due to the limitations of the parallel port interface.

  See ``DE-600 / DE-620'' and ``RealTek'' for supported pocket adaptors.

  You can sometimes avoid the wall-brick with the adaptors by buying or
  making a cable that draws power from the laptop's keyboard port. (See
  ``keyboard power'')

  10.  Miscellaneous.

  Any other associated stuff that didn't fit in anywhere else gets
  dumped here. It may not be relevant, and it may not be of general
  interest but it is here anyway.

  10.1.  Passing Ethernet Arguments to the Kernel

  Here are two generic kernel commands  that can be passed to the kernel
  at boot time. This can be done with LILO, loadlin, or any other
  booting utility that accepts optional arguments.

  For example, if the command was `blah' and it expected 3 arguments
  (say 123, 456, and 789) then, with LILO, you would use:

  LILO: linux blah=123,456,789

  Note: PCI cards have their i/o and IRQ assigned by the BIOS at boot.
  This means that any boot time arguments for a PCI card's IRQ or i/o
  ports are usually ignored.

  For more information on (and a complete list of) boot time arguments,
  please see the BootPrompt-HOWTO
  <http://sunsite.unc.edu/mdw/HOWTO/BootPrompt-HOWTO.html>

  10.1.1.  The ether command

  In its most generic form, it looks something like this:

       ether=IRQ,BASE_ADDR,PARAM_1,PARAM_2,NAME

  All arguments are optional.  The first non-numeric argument is taken
  as the NAME.

  IRQ: Obvious.  An IRQ value of `0' (usually the default) means to
  autoIRQ.  It's a historical accident that the IRQ setting is first
  rather than the base_addr -- this will be fixed whenever something
  else changes.

  BASE_ADDR: Also obvious.  A value of `0' (usually the default) means
  to probe a card-type-specific address list for an ethercard.

  PARAM_1: It was orginally used as an override value for the memory
  start for a shared-memory ethercard, like the WD80*3.  Some drivers
  use the low four bits of this value to set the debug message level.  0
  -- default, 1-7 -- level 1..7, (7 is maximum verbosity)  8 -- level 0
  (no messages). Also, the LANCE driver uses the low four bits of this
  value to select the DMA channel.  Otherwise it uses auto-DMA.

  PARAM_2: The 3c503 driver uses this to select between the internal and
  external transceivers.  0 -- default/internal, 1 -- AUI external.  The
  Cabletron E21XX card also uses the low 4 bits of PARAM_2 to select the
  output media. Otherwise it detects automatically.

  NAME: Selects the network device the values refer to.  The standard
  kernel uses the names `eth0', `eth1', `eth2' and `eth3' for bus-
  attached ethercards, and `atp0' for the parallel port `pocket'
  ethernet adaptor. The arcnet driver uses `arc0' as its name.  The
  default setting is for a single ethercard to be probed for as `eth0'.
  Multiple cards can only be enabled by explicitly setting up their base
  address using these LILO parameters.  The 1.0 kernel has LANCE-based
  ethercards as a special case.  LILO arguments are ignored, and LANCE
  cards are always assigned `eth<n>' names starting at `eth0'.
  Additional non-LANCE ethercards must be explicitly assigned to
  `eth<n+1>', and the usual `eth0' probe disabled with something like
  `ether=0,-1,eth0'.  ( Yes, this is bug. )

  10.1.2.  The reserve command

  This next lilo command is used just like `ether=' above, ie. it is
  appended to the name of the boot select specified in lilo.conf

       reserve=IO-base,extent{,IO-base,extent...}

  In some machines it may be necessary to prevent device drivers from
  checking for devices (auto-probing) in a specific region. This may be
  because of poorly designed hardware that causes the boot to freeze
  (such as some ethercards), hardware that is mistakenly identified,
  hardware whose state is changed by an earlier probe, or merely
  hardware you don't want the kernel to initialize.

  The reserve boot-time argument addresses this problem by specifying an
  I/O port region that shouldn't be probed. That region is reserved in
  the kernel's port registration table as if a device has already been
  found in that region. Note that this mechanism shouldn't be necessary
  on most machines. Only when there is a problem or special case would
  it be necessary to use this.

  The I/O ports in the specified region are protected against device
  probes. This was put in to be used when some driver was hanging on a
  NE2000, or misidentifying some other device as its own.  A correct
  device driver shouldn't probe a reserved region, unless another boot
  argument explicitly specifies that it do so.  This implies that
  reserve will most often be used with some other boot argument. Hence
  if you specify a reserve region to protect a specific device, you must
  generally specify an explicit probe for that device. Most drivers
  ignore the port registration table if they are given an explicit
  address.

  For example, the boot line

       LILO: linux  reserve=0x300,32  ether=0,0x300,eth0

  keeps all device drivers except the ethercard drivers from probing
  0x300-0x31f.

  As usual with boot-time specifiers there is an 11 parameter limit,
  thus you can only specify 5 reserved regions per reserve keyword.
  Multiple reserve specifiers will work if you have an unusually
  complicated request.

  10.2.  Using the Ethernet Drivers as Modules

  See the insmod(8) manual page for information on passing arguments to
  the module as it is being loaded.  The command lsmod will show you
  what modules are loaded, and rmmod will remove them.

  At present, all the modules are put in the subdirectory modules in
  your Linux kernel source tree (usually in the form of symbolic links).
  To actually generate the modules, you have to type make modules after
  you have finished building the kernel proper. Earlier kernels built
  them automatically, which wasn't fair to those compiling on 4MB
  386sx-16 machines.

  Most modules accept parameters like io=0x340 and irq=12 on the insmod
  command line. It is STRONGLY ADVISED that you supply these parameters
  to avoid probing for the card. Unlike PCI and EISA devices, there is
  no real safe way to do auto-probing for ISA devices, and so it should
  be avoided when using drivers as modules.

  A list of all the parameters that each module accepts can be found in
  the file:

  /usr/src/linux/Documentation/networking/net-modules.txt

  It is recommended that you read that to find out what options you can
  use for your particular card.

  Once you have figured out the arguments/options you are going to use,
  you can insert the module by typing as root:

  ______________________________________________________________________
          insmod mod_name.o [io=val1[,val2,...]] [irq=val7[,val8,...]]
  ______________________________________________________________________

  The comma separated value lists are used for modules that have the
  capability to handle multiple devices from a single module, such as
  all the 8390 drivers, and the PLIP driver.

  Once a module is inserted, then you can use it just like normal, and
  give ifconfig commands. If you set up your networking at boot, then
  make sure your /etc/rc* files run the insmod command(s) before getting
  to the ifconfig command.

  Also note that a busy module can't be removed. That means that you
  will have to ifconfig eth0 down  (shut down the ethernet card) before
  you can remove the module(s).

  10.2.1.  8390 Based Cards as Modules

  The present list of 8390 based drivers is: 3c503, ac3200, e2100, hp,
  hp-plus, ne, smc-ultra and wd. These cards were not supported as
  modules for kernel versions prior to 1.3.42.  (This does not include
  some of the separately distributed PCMCIA drivers (e.g. de-650) that
  are also 8390 based, that have had module support for quite some time
  now.)

  If you have an 8390 based card, you may have to insert two modules,
  8390.o and then the module for your card.  If 8390 support has been
  built into your kernel, then you will not need to insert the 8390
  module. (8390 support is built in whenever an 8390 based card is
  selected to be built into the kernel.) Doing a cat /proc/ksyms | grep
  8390 will tell you if 8390 support is in your kernel.

  For an 8390 based card, you will have to remove the card module before
  removing the 8390 module, as the 8390 module is used by the card
  module, and thus marked as busy.

  The 8390 series of network drivers now support multiple card systems
  without reloading the same module multiple times (memory efficient!)
  This is done by specifying multiple comma separated values, such as:

  ______________________________________________________________________
          insmod 3c503.o io=0x280,0x300,0x330,0x350 xcvr=0,1,0,1
  ______________________________________________________________________

  The above would have the one module controlling four 3c503 cards, with
  card 2 and 4 using external transcievers.

  It is *STRONGLY RECOMMENDED* that you supply "io=" instead of
  autoprobing.  If an "io=" argument is not supplied, then the ISA 8390
  drivers will complain about autoprobing being not recommended, and
  begrudgingly autoprobe for a *SINGLE CARD ONLY* -- if you want to use
  multiple cards you *have* to supply an "io=0xNNN,0xQQQ,..." argument.

  The ne module is an exception to the above. A NE2000 is essentially an
  8390 chip, some bus glue and some RAM.  Because of this, the ne probe
  is more invasive than the rest, and so at boot we make sure the ne
  probe is done last of all the 8390 cards (so that it won't trip over
  other 8390 based cards) With modules we can't ensure that all other
  non-ne 8390 cards have already been found. Because of this, the ne
  module REQUIRES an io=0xNNN argument passed in via insmod. It will
  refuse to autoprobe.

  It is also worth noting that auto-IRQ probably isn't as reliable
  during the flurry of interrupt activity on a running machine. Cards
  such as the ne2000 that can't get the IRQ setting from an EEPROM or
  configuration register are probably best supplied with an irq=M
  argument as well. The file

  /usr/src/linux/Documentation/networking/net-modules.txt

  also lists how the interrupt settings are determined for the various
  cards if an irq=N value is not given.

  10.3.  Mailing Lists and the Linux Newsgroups

  If you have questions about your ethernet card, please READ this
  document first. You may also want to join the NET channel of the Linux
  mailing lists by sending mail to [e-mail] to get
  help with what lists are available, and how to join them.

  Furthermore keep in mind that the NET channel is for development
  discussions only. General questions on how to configure your system
  should be directed to comp.os.linux.setup unless you are actively
  involved in the development of part of the networking for Linux.  We
  ask that you please respect this general guideline for content.

  Also, the news groups comp.sys.ibm.pc.hardware.networking and
  comp.dcom.lans.ethernet should be used for questions that are not
  Linux specific.

  10.4.  Related Documentation

  Much of this info came from saved postings from the comp.os.linux
  groups, which shows that it is a valuable resource of information.
  Other useful information came from a bunch of small files by Donald
  himself. Of course, if you are setting up an Ethernet card, then you
  will want to read the NET-2 Howto so that you can actually configure
  the software you will use.  Also, if you fancy yourself as a bit of a
  hacker, you can always scrounge some additional info from the driver
  source files as well. There is usually a paragraph or two in there
  describing any important points before any actual code starts..

  For those looking for information that is not specific in any way to
  Linux (i.e. what is 10BaseT, what is AUI, what does a hub do, etc.)  I
  strongly recommend the Ethernet-FAQ  that is posted regularly to the
  newsgroup comp.dcom.lans.ethernet.  You can grab it from RTFM which
  holds all the newsgroup FAQs at the following URL:

  Usenet FAQs <ftp://rtfm.mit.edu/pub/usenet-by-hierarchy/>

  You can also have a look at the `Ethernet-HomePage' so to speak, which
  is at the following URL:
  Ethernet-HomePage <http://wwwhost.ots.utexas.edu/ethernet/ethernet-
  home.html>

  10.5.  Contributors

  Other people who have contributed (directly or indirectly) to the
  Ethernet-Howto are, in alphabetical order:

          Ross Biro               <[e-mail]>
          Alan Cox                <[e-mail]>
          David C. Davies         <[e-mail]>
          Bjorn Ekwall            <[e-mail]>
          David Hinds             <[e-mail]>
          Michael Hipp            <[e-mail]>
          Mike Jagdis             <[e-mail]>
          Duke Kamstra            <[e-mail]>
          Russell Nelson          <[e-mail]>
          Cameron Spitzer         <[e-mail]>
          Dave Roberts            <[e-mail]>
          Glenn Talbott           <[e-mail]>

  These mail addresses are intentionally not `mailto' links so as to
  protect these people from WWW `spam-bot' filters.  Many thanks to the
  above people, and all the other unmentioned testers out there.

  10.6.  Disclaimer and Copyright

  This document is not gospel. However, it is probably the most up to
  date info that you will be able to find. Nobody is responsible for
  what happens to your hardware but yourself. If your ethercard or any
  other hardware goes up in smoke (...nearly impossible!)  we take no
  responsibility. ie. THE AUTHORS ARE NOT RESPONSIBLE FOR ANY DAMAGES
  INCURRED DUE TO ACTIONS TAKEN BASED ON THE INFORMATION INCLUDED IN
  THIS DOCUMENT.

  This document is Copyright (c) 1993-1997 by Paul Gortmaker.
  Permission is granted to make and distribute verbatim copies of this
  manual provided the copyright notice and this permission notice are
  preserved on all copies.

  Permission is granted to copy and distribute modified versions of this
  document under the conditions for verbatim copying, provided that this
  copyright notice is included exactly as in the original, and that the
  entire resulting derived work is distributed under the terms of a
  permission notice identical to this one.

  Permission is granted to copy and distribute translations of this
  document into another language, under the above conditions for
  modified versions.

  If you are intending to incorporate this document into a published
  work, please make contact (vai e-mail) so that you can be supplied
  with the most up to date information available. In the past, out of
  date versions of the Linux HowTo documents have been published, which
  caused the developers undue grief from being plagued with questions
  that were already answered in the up to date versions.

  10.7.  Closing

  If you have found any glaring typos, or outdated info in this
  document, please send an e-mail. It's getting big, and it is easy to
  overlook stuff. If you have e-mailed about a change, and it hasn't
  been included in the next version, please don't hesitate to send it
  again, as it might have got lost amongst the usual sea of SPAM and
  junk mail.

  Thanks!