DHCP(8) DHCP(8)
NAME
dhcp - configure network interface details using DHCP
SYNOPSIS
ip/dhcp [ -bdmpr ] [ -g gateway ] [ -h hostname ] [ -x net ]
ifcdir [ localip [ localmask ]]
DESCRIPTION
Dhcp uses the Dynamic Host Configuration Protocol (DHCP) to
configure the ip(3) interface represented by ifcdir (eg,
/net/ipifc/1). The interface must have a device already
bound to it. Dhcp uses the MAC address of that device in
its requests.
Dhcp broadcasts a DHCP request for an address and various
network parameters. It takes the first acceptable offer,
sets the interface to that address, and writes the address
and parameter values, in ndb(6) format, to /net/ndb, where
cs(8), dns(8) and others will find them. If the address is
provided with a limited lease, dhcp itself returns, but it
leaves a process in the background that periodically renews
the lease (or requests a new address if the lease is not
renewed).
If localip is given, dhcp attempts to reacquire that
address. If successful, it configures the interface with
that address (and mask if supplied), maintaining any lease
as before. If it cannot reacquire the address, it broad-
casts a request for a new address, as above.
The options are:
-b Use plain BOOTP without the DHCP options
-d Enable debugging output on standard output
-g gateway
Suggest gateway as the default gateway (the server
might change it)
-h hostname
Use hostname as the current host's name in DHCP mes-
sages
-m Monitor the DHCP status and print a summary on standard
output whenever it changes
-n Do not configure the interface
-p Print the resulting configuration on standard output
Page 1 Plan 9 (printed 11/23/24)
DHCP(8) DHCP(8)
-r Retry DHCP periodically until it succeeds
-x net
Use mount point net to access the network, and write
the results to net/ndb (default: /net)
EXAMPLE
Allocate a new interface, bind an ether device to it, and
configure it with dhcp:
x=`{cat /net/ipifc/clone}
echo bind ether /net/ether0 >/net/ipifc/$x/ctl &&
ip/dhcp /net/ipifc/$x
SOURCE
/appl/cmd/ip/dhcp.b
SEE ALSO
ip(3), ndb(6), cs(8), dns(8)
DIAGNOSTICS
Dhcp returns an error status if it receives no acceptable
reply, unless the -r option is given to force retries.
Page 2 Plan 9 (printed 11/23/24)