UDHCPC(8)						 GNU/Linux Administrator's Manual						 UDHCPC(8)

NAME

       udhcpc - very small DHCP client

SYNOPSIS

       udhcpc [OPTION]...

DESCRIPTION

       The udhcp client negotiates a lease with the DHCP server and executes a script when it is obtained or lost.

OPTIONS

       -c CLIENTID, --clientid=CLIENTID
	      Send the client identifier CLIENTID.

       -f, --foreground
	      Do not fork after obtaining a lease.

       -H HOSTNAME, --hostname=HOSTNAME
	      Send the client hostname HOSTNAME.

       -h HOSTNAME
	      Alias for -H HOSTNAME.

       -i INTERFACE, --interface=INTERFACE
	      Configure INTERFACE.

       -n, --now
	      Exit with failure if a lease cannot be obtained.

       -p FILE, --pidfile=FILE
	      Write the process ID of the daemon to FILE.

       -q, --quit
	      Exit after obtaining a lease.

       -r ADDRESS, --request=ADDRESS
	      Request IP address ADDRESS.

       -s FILE, --script=FILE
	      Use script FILE.

       -v, --version
	      Display version.

USAGE

       When an event occurs, udhcpc executes a script.	There are four possible arguments to this script:

       deconfig
	      deconfig	is  used  when	udhcpc	starts, and when a lease is lost.  The script should put the interface in an up, but deconfigured,
	      state.

       bound  bound is used when udhcpc moves from an unbound to a bound state.  The script should configure the interface and set any other rele-
	      vant parameters (e.g., default gateway, dns server, etc.).

       renew  renew  is  used when udhcpc when a lease is renewed.  The interface is already configured, so the IP address will not change.  Other
	      parameters (e.g., default gateway, subnet mask, dns server) may.

       nak    nak is used when udhcpc receieves a NAK packet from the server. The enviromental variable $message will contain the reason  for  the
	      NAK message if the server included one. Processing this message is optional, as the script will also be called with deconfig if need
	      be.

       Parameters are passed to the script via the following environment variables:

       HOME   The inherited HOME, or "/" if it is unset.

       PATH   The inherited PATH, or "/bin:/usr/bin:/sbin:/usr/sbin" if it is unset.

       interface
	      The interface.

       ip     The client IP address.

       siaddr The BOOTP next server option.

       sname  The BOOTP server name option.

       boot_file
	      The BOOTP boot file option.

       subnet The subnet mask.

       timezone
	      The timezone offset from UTC in seconds.

       router The list of routers.

       timesvr
	      The list of time servers.

       namesvr
	      The list of IEN 116 name servers.

       dns    The list of DNS servers.

       logsvr The list of MIT-LCS UDP log servers.

       cookiesvr
	      The list of RFC 865 cookie servers.

       lprsvr The list of LPR servers.

       hostname
	      The host name.

       bootsize
	      The length in 512-octet blocks of the bootfile.

       domain The domain name of the network.

       swapsvr
	      The client's swap server.

       rootpath
	      The path of the client's root dist.

       ipttl  The TTL.

       mtu    The MTU.

       broadcast
	      The broadcast address.

       ntpsrv The list of NTP servers.

       wins   The list of WINS servers.

       lease  The lease time in seconds.

       dhcptype
	      The DHCP message type (safely ignored).

       serverid
	      The server IP address.

       message
	      Reason for a DHCPNAK.

       tftp   The TFTP server name.

       bootfile
	      The bootfile name.

FILES

       /usr/share/udhcpc/default.script
	      Script run when leases are obtained or lost.

NOTES

       udhcpc responds to the following signals:

       SIGUSR1
	      This signal causes udhcpc to renew the current lease or, if it does not have one, obtain a new lease.

       SIGUSR2
	      This signal caused udhcpc to release the current lease.

GNU
/Linux							    2001-09-26								 UDHCPC(8)