The bootp command gives client hosts the ability
to obtain network configuration information
from a central Internet Bootstrap Protocol
(BOOTP) server (see
bootpd(1Mtcp)).
Files
/etc/inet/bootptab
database file read by bootpd
Usage
bootp can be run at system installation time,
or in cases where the characteristics of the network change
(for example, when a new domain name server is added)
and the client's configuration files must be updated
to reflect the changes to the network.
bootp can be run by a privileged user only.
When invoked,
bootp broadcasts a BOOTP request containing the
hardware address of the Ethernet interface interface_name
through the Ethernet device device.
bootpd responds to the request on the BOOTP server.
bootp interprets the response and outputs
attribute values contained in the response as shell variable assignments.
If a randomly varied time-out period expires without a response,
bootp resends the request and increases the time-out period.
The request is retried until number_of_tries
(default 5) is reached.
To avoid the possibility of exhausting the space in the 64 byte vend
area of the request/response packet, the host name and domain name attributes
are obtained via reverse DNS lookup.
The local
hosts(4tcp)
file and the
resolv.conf(4tcp)
file are not
consulted for this operation; any DNS servers specified
in the vend area are consulted instead.
The BOOTP attributes that are currently used,
together with the shell variables output by bootp,
are summarized in the following tables:
RFC 951
field name
BOOTP server
attribute name
BOOTP client
shell variable
file
bf
INET_BOOT_FILE_NAME
ciaddr
ip
INET_YOUR_IP_ADDRESS
siaddr
sa
INET_SERVER_IP_ADDRESS
vend
-
see following table
RFC 1533 vendor
extension field
BOOTP server
attribute name
BOOTP client
shell variable
Ethernet Frame Type
T36
INET_ETHER_ENCAPSULATION
NIS Domain Name
T40
INET_NIS_DOMAIN_NAME
Domain Name
dn
INET_DOMAIN_NAME
Domain Name Server
ds
INET_DNS_SERVER[instance]
Router
gw
INET_ROUTER[instance]
Host Name
hn
INET_HOSTNAME
Subnet Mask
sm
INET_SUBNET_MASK
Time Offset
to
INET_TIME_OFFSET
Time Server
ts
INET_TIME_SERVER[instance]
Note that, in cases where reverse DNS lookup is used,
bootp outputs
the INET_HOSTNAME and INET_DOMAIN_NAME variables.
The attribute names shown in these tables
are implemented as parameter declarations
in the BOOTP server configuration
file /etc/inet/bootptab
(see
bootptab(4tcp)).
Options
bootp takes the following options:
-ainterface_name
Causes the Ethernet interface interface_name
to be reconfigured with an address of zero.
interface_name should be
the name of the interface associated with the Ethernet device.
This allows bootp to receive a response
even if it is directed to a different IP address
because the current IP address does not match the BOOTP
server's configuration.
To avoid an error condition,
do not invoke bootp
with the -a option from a multi-user system
when interface_name is in use.
-cnumber_of_tries
Specifies the number of unanswered BOOTP
requests to send before giving up.
The default value is 5.
-d
Do not use DNS to obtain the host name and the domain name.
Exit codes
On success, bootp returns zero.
On a timeout, it returns 254
and prints the message
INET_BOOTP_TIMEDOUT=yes
to the standard error output.
The ht (hardware address type) and
ha (hardware address) attributes
are used by the BOOTP server
to locate the proper entry in its configuration file.
Note that this client host forces the BOOTP
server to choose an address
by always setting the ciaddr field in the request to zero.
The value of the bootp argument hostname is placed
in the request vend area ``Host Name'' field so that a server
may choose to respond based on this hostname
if a lookup by hardware address fails.
The Class Identifier of ``UnixWare'' is also provided in
the request to identify the client as a UnixWare system.