A Beginner's Guide to the Internet/INTERNET.ISO/text/faqs/venturin

Text File | 1995-03-13 | 27.2 KB | 692 lines

OIT Document G-064-1  August 1992





Venturing Into the Internet


Contents
Welcome to the Internet
Anatomy of Internet Addresses
Telnet
FTP
Anonymous FTP
Library Resources
Mailing Lists, Listservs, and Newsgroups




This document offers a bare-bones introduction to the
Internet.  Its goal is to describe the basic features of
the Internet and how to gain access to the resources that
are out there.  You should keep in mind that the resources
available on the Internet are changing and growing daily,
so by the time anything is documented, the information is
probably outdated.  Consequently, this document describes
what kinds of things are out there and gives you some
tools for investigating the Internet on your own.

An excellent source for learning more about the Internet ╤
the ins, outs, and rules for using it ╤ is Zen and the Art
of the Internet, by Brendan P. Kehoe. The guide is
available in Postscript and ascii formats via anonymous
ftp (explained later in this document) from
sunsite.unc.edu.  The guides are in pub/docs/about-the-
net/ZEN ╤ the filename for the Postscript version is zen-
1.0.PS and the filename for the ascii version is
zen10.TXT.

For information on using telnet and ftp under MVS, see OIT
document G-051, TCP/IP for MVS.
For information on bbs, see OIT document H-011, Extended
Bulletin Board Services at UNC-CH.

For information on connecting to OIT computers, see the
how-to sheet relevant to your computer setup.

H-004 How to Connect to Computing Services through the
Campus Sytek Network
H-005 How to Connect to Computing Services with an IBM
PC/Compatible and Procomm
H-006 How to Connect to Computing Services with an IBM
PC/Compatible and MS-Kermit
H-008 How to Connect to Computing Services with a
Macintosh and MacKermit
H-010 How to Connect to Computing Services with a
Macintosh and NCSA Telnet

OIT Help Desks ╤ OIT staffs two help desks: one in
Phillips Hall and one in the House Undergraduate Library.
The Phillips Hall help desk is room 37 (in the basement);
you can drop by with your questions, call them at 962-
0273, or send them electronic mail to [e-mail].
You can also drop by the help desk in the Undergraduate
Library, call them at 962-3601, or send them e-mail at
[e-mail].


WELCOME TO THE INTERNET

But what have you just been welcomed to? Simply
(oversimply) Internet is a collection of computer networks
around the world.  All computers on the Internet must use
the same protocol (similar to being able to speak the same
language) called TCP/IP.  While Internet is just a network
of machines, what it means for most people in their day-
to-day lives is public access to a considerable amount of
information.

But if you already use electronic mail and are content,
why should you care about Internet? What does the Internet
offer you? More information than just mail can bring you,
perhaps more than you want.  For example, you can get a
wide variety of documentation and publications in almost
every field imaginable.  You can get weather  information,
geographical data, phone numbers and addresses, and
literature texts.  Public domain software is also "out on
the net" and is yours simply for the taking (via anonymous
FTP, explained later). You can subscribe to electronic
publications and research databases. And then there are
the "news groups," electronic discussion groups covering
almost every imaginable topic.  Through Internet you can
also search through many university library card catalogs
and often other library resources.

FINDING THE INTERNET'S RESOURCES

That depends on where you're starting.   But one thing to
remember is that the Internet isn't a computer so you
can't "dial-in" to it.  There are three basic ways to get
on the Internet:

*     Log on to to a computer that is on the Internet
(such as any of the computers OIT operates)

*     Your microcomputer or workstation can be on the
Internet if it's on the campus network (probably with an
Ethernet connection) and runs TCP/IP software (such as
NCSA Telnet or TN3270 on the Macintosh, or Clarkson Telnet
or LAN Workplace on DOS machines)

*     Connect to the UNC-OIT BBS, a free system on which
you create your own account (no userid required).
Advantages to using the BBS are that you don't have to
have an account on an OIT computer or have a microcomputer
on the campus network and it's free.  A disadvantage is
that you can't  connect directly to other machines (have a
Telnet session) or transfer files via an FTP session.
However, the BBS does offer a menu to assist you in
getting to public offerings.  For more information on BBS,
see OIT document H-011, Extended Bulletin Board Services
at UNC-CH.

If you don't know if your microcomputer is on the
Internet, ask your network manager or your department's
computer support person.

What are the drawbacks of using the Internet?
To hear some people talk, you would think the answer to
this question would be "there are none." But that's not
quite true. While being able to check university library
holdings and other online resources can be a great help,
it can be frustrating when you aren't familiar with that
library's computer system or don't even know what system
it uses.  However,  on their welcome screens most
libraries and other services now give fairly good
instructions for using their system.   Read welcome
screens carefully!

Terminal emulation can also cause problems.  If you're
emulating a vt100 and the system to which you connect is
expecting a 3270 (IBM) terminal, you may not be able to
use the keys the system tells you to use (a hint, if the
system tells you to use cursor keys to make selections and
your cursor keys aren't working, try using the tab
instead).

You also need to keep in mind that you have restricted
access to the network computers ╤ connecting to a computer
doesn't automatically give you full access to all the
computers and their resources (for example, all the data
they store or the applications they run).  For complete
access you need to have a userid for each computer you
want to use.  However, as the Internet grows, the
information with public access also grows.


ANATOMY OF INTERNET ADDRESSES

An e-mail address on the Internet consists of a person's
account or userid, the name and location of the computer
(which may have several parts) and the domain (the kind of
organization which owns the computer).  The address is
similar to a U.S. postal address insofar as with each
level (in Internet addresses the levels are separated by
periods) the information gets more general.  For example,
postal addresses go from a person's name to the apartment
number, street name, city, state, and finally to the
country when necessary.  An Internet address follows the
same logic moving from the userid, to the computer name,
department name, university, and finally the domain.  For
example, the Internet address of someone on the OIT VAX
computer would be [e-mail] ╤ userid
identifies the person; uncvx1 is the name of the OIT VAX
computer;  oit specifies the department which owns the
computer; unc identifies the institution to which OIT
belongs; and edu, the domain, shows that UNC is an
educational institution.

Other domains are

com     commercial organization
gov     government
mil     military
net     network administration
org     private organizations that don't fit into the
other categories

Countries also have domain designations.  Some common
country designations are

au     Australia
ca     Canada
fr     France
uk     United Kingdom

Each machine name also has a corresponding number (called
an IP or Internet Protocol number).  For example, you can
refer to the OIT VAX as either uncvx1.oit.unc.edu or as
128.109.157.1. IP numbers aren't as stable as name
addresses because sites occasionally need to change an IP
number but usually don't change the name addresses.
Consequently, whenever possible use the name address.

FINDING INTERNET EMAIL ADDRESSES

By far the easiest (and sometimes fastest) way to find an
e-mail address is to call the person to whom you want to
send the mail and ask.  You can find UNC-CH faculty and
staff e-mail addresses in the campus phone book (which is
also online in Info* ).

However, you can also find address information over the
network.  The local WAIS (Wide Area Information Server) on
the bbs gives information on how to find mail addresses at
different colleges.  Log onto the bbs and  from the menu
choose the "Simple WAIS Client."  From there, conduct a
search of the College E-mail server by using the college
or university name as a keyword.  You need to be aware,
though, that the server does not give you actual e-mail
addresses, but tells you how various colleges and
universities organize their userids and when possible
tells you how  to find  e-mail addresses for people on
that campus.


TELNET

Telnet is a communications protocol that allows you to be
connected with one computer (the host computer) on the
Internet and from there connect and work on another
(remote) computer. For example, if you have a userid for
the OIT VAX computer (uncvx1) and also one for the OIT IBM
computer (uncmvs), you can connect to the VAX and then
from it connect to MVS via Telnet.  Since Telnet doesn't
use phone lines (as a modem would), the connection is
virtually error free and it's also usually faster than
connecting via "dial-up" modems.  You can use telnet to
connect to any machine on the Internet (but only to
machines on the Internet).

If your microcomputer is already on the Internet (it runs
TCP/IP software such as Clarkson Telnet or NCSA Telnet),
then you can connect to other Internet computers without
logging on to another computer first.  However, for all
intents and purposes, you can't telnet to another
microcomputer.  Ask your network manager or computer
support person for information on how your computer is set
up.

To connect to a remote computer, you must first log onto a
computer with Internet access.  Once logged on, issue the
command telnet followed by the Internet address of the
computer you want to connect to. For example, to connect
to the samba on campus, once you were logged onto a
computer on the Internet you would enter

     telnet samba.oit.unc.edu

You'll then be connected to the remote computer (in the
example above, to samba).  The remote system will prompt
you for its customary logon information and then you can
proceed as you customarily would.  Logging off the remote
system ends the Telnet session and returns you to the
system where you started.

Remember that getting to the machine is one thing, and
having access to its resources is another ╤ unless you are
using a public resource (such as library catalogs, public
databases) you'll usually need your own userid to use the
machine's resources.


When using telnet, the function keys for the remote system
might not work, especially if you are connecting to an IBM
system (such as MVS or VM) from a non-IBM system.  Telnet
emulates a vt100 terminal, whereas MVS and VM will be
expecting 3270 terminal emulation.


FTP

One of the most valuable things an Internet connection
offers is FTP (file transfer protocol), a relatively easy
and fast way to  transfer files from one machine on the
Internet to another.  Unless you are doing an anonymous
ftp (described below), to transfer files you must have
access authority (a userid) for both machines you plan to
use ╤ the one from which you want to get the material and
the one where you want to put it.

Just as with Telnet, if your microcomputer is already on
the Internet (it runs TCP/IP software such as Clarkson
Telnet or NCSA Telnet), there are several microcomputer
programs you can use to FTP files between your micro and
an Internet site without having to log onto a mainframe
computer first.   For more information about these
programs, call one of the OIT help desks.


BASIC FTP STEPS

Whenever you use FTP, you should remember that although
you establish a connection with a remote computer, you
don't actually log on to the extent that you log onto a
machine and can use its resources. With FTP, you connect
to the machine, identify yourself to it, and then you can
move files to and from the machine ╤ you can't run any of
its applications.  The basic steps for transferring files
are listed below.

If you are using a microcomputer that has Internet access
(i.e., you don't need to log onto another computer to get
Internet access), you won't need to follow these
directions.  Instead, you can use one of the many
available FTP applications.  Although the way in which you
execute the ftp commands may be different, the basic steps
will follow those outlined below.

1.     Log onto a computer on the Internet.

2.     Start the FTP session by entering the command ftp.

3.     Tell the system what remote computer you want to
use by entering the command open site_id substituting the
computer name for site_id. For example, open
uncvx1.oit.unc.edu.  (On some systems you can combine
steps 1 and 2 by specifying the remote system with the ftp
command: ftp uncvx1.oit.unc.edu.)

4.     Enter your userid and password when the remote
system prompts you for them.  Or enter anonymous for
anonymous ftp (anonymous ftp is described below).

5.     Get a directory listing of files and directories
with the ls or dir commands ╤ ls gives only the names of
files and directories; dir gives a more complete listing,
showing, among other things, sizes of the files and file
types.

6.     If you need to change to another directory, give
the command cd followed by the directory name (for
example, cd pubs).  Enter cd ..  (cd followed by a space
and then two periods) to return to an earlier directory
(one higher in the hierarchy).

7.     Once you are in the directory that has the file you
want, to transfer the file enter either the get (copy a
file from the remote computer to the local one)  or the
put command (copy a file from the local one to the remote
one) followed by the file name, as in

     get zen-1.0.PS
or
     put zen-1.0.PS

Remember the local computer is the one from which you
issued the ftp command.

8.     To end the FTP session, enter quit.


FILE TYPES

If you're transferring files that aren't ASCII or text
files (for example, binary  or image files), you may need
to specify the file type. The standard commands are set
file binary and set file text, but different computing
systems can have different commands.  For more information
on specifying file types, try using the help command
(after you've given the ftp command), refer to Zen and the
Art of the Internet,  or call the user services help desk.


DIRECTORY HIERARCHIES AND CONVENTIONS
Usually when people tell you where a file is on the
Internet, they give you something that includes many
slashes indicating a hierarchy of directories. For
example, at the beginning of this document we mention that
you can get Zen and the Art of the Internet from
sunsite.unc.edu under pub/docs.  Once you log onto
sunsite, you need to change to the pub directory (give the
command cd pub), change to the doc directory (give the
command cd doc), change to the about-the-net directory,
and then change to the ZEN directory.  It's generally a
good idea to get a directory listing each time you change
the directory.


OTHER HELPFUL FTP COMMANDS

You can transfer several files simultaneously with mget
and mput, the standard commands for transferring several
files at one time. To use the commands, after the mget or
mput command list the files you want to transfer and
separate the file names with a comma: MGET
file1.txt,file2.txt,file3.txt.


ANONYMOUS FTP

Many computer sites make files and free software available
to all Internet users via anonymous ftp, a way for users
to get files from a machine without needing a userid for
that specific machine.  The process for transferring the
files is the same as that for a regular FTP, except that
when prompted for a username or userid, you enter
anonymous.  When prompted for your password, enter your e-
mail address.

If you're planning on transferring large files that will
require considerable time and resources to copy, you
should plan to transfer the file after normal business
hours for that site.  This way, you won't be interfering
with people at that site who are trying to use the machine
for work.

FINDING WHAT'S AVAILABLE FOR ANONYMOUS FTP

There's a lot out there for the taking, but how do you
find it?  Word of mouth is one way and is still probably
the most popular.  If you read newsgroups (described
below) or subscribe to a list, you probably will hear
about files available over the net.  However, there are
some other ways for you to find such information.

Word of Warning:  Whenever you're looking for
files/programs, watch release dates and version numbers ╤
some of the information can be quite old.  There's also
never a guarantee that the newest version you find is in
fact the most recent version. Also, there is always a
remote chance there may be a virus in the downloaded
software, so be sure you have virus protection on your
microcomputer.

ARCHIE ╤ If you have the name of a file but you don't know
where the file is available for anonymous ftp, Archie can
help you.  Archie is a query system, designed by  McGill
University in Canada, that keeps up with what is available
at the more than 800 anonymous FTP sites.  Archie is
updated once a month.

To use Archie, telnet to one of the following archie
servers:

archie.ans.net     New York
archie.rutgers.edu     New Jersey
archie.sura.net     Maryland
archie.unl.edu     Nebraska
archie.mcgill.ca     Canada (the first Archie server)

At the login prompt, enter archie, and after a welcome
message the command prompt will be archie>.  To search for
a particular file, type prog followed by the file name
you're searching.  Archie should then respond with a list
of sites that have the file available for anonymous ftp.
You can also send a mail message to [e-mail]
making the body of your message prog file name.  This
method uses fewer resources than the previous ones, and it
gives you a file (responds with a mail message) so if the
search results in many matches you can review it at your
own leisure.

whatis database  ╤ Archie also maintains a database called
whatis with descriptive information for much of the public
domain software available on the Internet. To use the
whatis database, at the archie prompt enter whatis
followed  by the software or file name.  Keep in mind that
whatis does not contain descriptions of everything
available on the net and that it depends on the user
community for updates.

Finding Microcomputer Applications

Some sites act as repositories for microcomputer freeware
and shareware.  The repositories are updated regularly and
their files are available via anonymous ftp.

Macintosh Applications and Files ╤  SUMEX, at Stanford
University, is a repository for Macintosh software (free
and shareware), images, and documents.  The Internet
address for SUMEX is sumex-aim.stanford.edu.  When
connecting through anonymous FTP, you first get a
directory that contains several items, one of which is
info-mac, the Macintosh repository.  Change the directory
to info-mac; the info-mac directory is itself divided into
numerous directories.  Some of the things you can get from
sumex are the free virus fighters Disinfectant and
Gatekeeper.  There is also a complete archive of info-mac
digest (in the digest directory) and tidbits (an
electronic Mac magazine, also in the digest directory).

SUMEX now limits the number of people who can
simultaneously log on during working hours, so you may get
a message saying that you can't log on ╤ just try again
later.  Whenever possible, connect to SUMEX only after
regular business hours (keeping in mind that California is
in a different time zone).  Also, the numerous directories
often have readme files that give you valuable information
on the repository, what it contains, and the numerous ways
you can access it.

DOS Applications and Files ╤ WUARCHIVE, which resides at
Washington University in St. Louis, is a repository for
DOS files.  Its offerings are similar to those at SUMEX
except that it has dos-based information and applications.
The Internet address is wuarchive.wustl.edu.  Once there,
go to mirrors/msdos.  As with SUMEX, you should connect to
WUARCHIVE after business hours. (WUARCHIVE also has
essentially the same Mac files as SUMEX has except it can
sometimes be about a week behind SUMEX. The Macintosh
files are in mirrors/info-mac.)

You'll find extensive Windows applications and files at
ftp.cica.indiana.edu in pub/pc/win3 (note that ftp is the
beginning of the address and not the ftp command).



LIBRARY RESOURCES

Many colleges and universities have computerized their
card catalogs and made them accessible via the Internet.
You can connect to these libraries directly with Telnet.
However, an even easier way to get to the libraries is via
the OIT VAX computer or the campus BBS .  Most of the
online catalogs have some form of online help, but for the
most part you are on your own when it comes to figuring
out how to use the systems.   You should keep in mind,
though, that not all the resources are for public access
(for example, encyclopedia and journal databases).
Resources that are privately licensed are unavailable to
people who aren't associated with the libraries.   They
may appear on the menus but refuse access to you when you
request them.

Getting to UNC libraries:  Right now the UNC libraries are
not available directly from the Internet (this situation
will be changing, though, in the near future).  However,
you can get access to the UNC library catalog via VMS and
BBS, as well as through dialing up the campus broadband.

Libraries via VMS

To connect to libraries via VMS you don't need a userid or
account on the OIT VAX computer.  Connect to VMS
(uncvx1.oit.unc.edu)and when prompted for a userid enter
libtel.   You'll be given a menu of states.  Choose the
state you want and then you'll be given a list of
available libraries.  If you have a VMS userid, you can
issue libtel as a command.

Libraries via BBS

To connect to libraries via the BBS, first connect to BBS
and then choose 9 for libraries and campus wide
information services.  From there you'll be given a menu
of states.  Choose the state you want and then you'll be
given a list of available libraries.


CONNECTING TO LIBRARIES DIRECTLY

The list of Internet-accessible libraries (often called
the St. George directory because it is is maintained by
Art St. George and Ron Larsen) is much too long to include
here. However, you can get it over the net via anonymous
ftp. The directory is available locally at sunsite.unc.edu
in pub/docs, and the filename is library.guide. The guide
is also at nic.cerf.net in the directory
cerfnet/cerfnet_info/library_catalog. The file name for
the listing is internet-catalogs and has a date suffix.
FTP the most recent date.

Another very helpful directory, maintained at the
University of North Texas, lists not only the libraries
but also the Internet address, login and logoff
instructions, system vendor, and information on how to use
the database.  The North Texas directory lists the
libraries in alphabetic order according to institution.
You can get it via anonymous ftp from  sunsite.unc.edu.
The file is in the directory pub/docs and the file name is
LIBRARIES.TXT.

There's also a news group that announces new libraries on
the net and discusses other related topics.  The group is
called comp.internet.library (news groups are described
below).

CARL ╤ The Colorado Alliance of Research Libraries
The Colorado Alliance of Research Libraries (CARL) is a
network of libraries (not just one library) whose
resources are made available as a group.  In addition to
having card catalogues on the network, they also make
numerous databases available.  Facts on File and Choice
Book Reviews are two interesting resources offered by
CARL.   To reach CARL, telnet to pac.carl.org.  If you
want more information on CARL, you can send e-mail to
[e-mail].

By selecting services you move from one library site to
another (a good thing to remember is that usually //exit
will return you "home" ╤ to the site you began with, which
in this case is Denver).


MAILING LISTS, LISTSERVS, AND NEWSGROUPS

Networks have meant not only that people can connect to
distant machines and their resources, but that people can
connect to each other.  Discussion groups exist for almost
any topic you can imagine and the number of groups is
always growing.  Mail listservs, which exist on BITNET
(another network) is an automated way of sending mail to a
defined list of people.  To be part of a discussion, you
subscribe to the list, usually by sending a subscription
message to the listserv.

Mailing lists on the Internet are similar to BITNET's
listservs.  To subscribe you usually will send a
subscription request to a version of the mailing list that
has -request in its name.  Don't send the request to the
regular list  ╤ people on the list can't help you join the
group and after a short time get quite irritated with
subscription requests flooding their mailboxes.

You can get a directory of mailing lists via anonymous ftp
from sunsite.unc.edu in pub/docs. The file is named
interest-groups.

Usenet news accomplishes much the same goal as listservs
and mailing lists, but the messages aren't sent to your
mailbox and you don't use your mail system to read or post
messages.   To read the articles, you connect to a
computer that carries Usenet News and from there you
choose what groups you want to read.  How you read the
news also varies according to the machine carrying the
news and the machine you are using for the connection.

At UNC, one of the ways to read news is to connect to the
OIT BBS system.  There are also several programs that make
reading news even easier if you have a Macintosh or PC and
an Ethernet connection.

Newsgroups cover every imaginable topic and then some.
Some groups are moderated, which means someone screens
articles so that the group isn't flooded with irrelevant
postings.  Groups are organized according to category and
the group name's prefix shows the category.  The main
categories are listed below:

comp     computer-related topics such as software,
hardware, and computer science. These groups are usually
identified by computing system.

misc     miscellaneous topics that don't fit well in other
categories

sci     sciences

soc     social and cultural issues (broadly defined)

talk     often features long debates

news     the news network and related issues on software
and groups

rec     hobbies, recreation

alt     "alternative" ╤ and just about anything can and
does show up in this group.

gnu     GNU Project of the Free Software Foundation

biz     business-oriented topics

Keep in mind that these news groups do not allow anything
that even resembles commercial advertising.  A quick way
to get in trouble is to try to sell your own product over
the net.

If you want more information on Usenet, see Zen and the
Art of the Internet.


* Info is the online campuswide information system. See
the OIT how-to sheets for connecting to services for more
information on getting to Info.