dhcrelay(8)

NAME
       dhcrelay - Dynamic Host Configuration Protocol Relay Agent

SYNOPSIS
       dhcrelay [ -p port ] [ -d ] [ -q ] [ -i if0 [ ...  -i  ifN
       ] ] server0 [ ...serverN ]

DESCRIPTION
       The  Internet Software Consortium DHCP Relay Agent, dhcre
       lay, provides a means for relaying DHCP and BOOTP requests
       from  a  subnet to which no DHCP server is directly to one
       or more DHCP servers on other subnets.

OPERATION
       The DHCP Relay Agent listens  for  DHCP  requests  on  all
       interfaces  attached  to a host, unless one or more inter
       faces are specified on the command line with the -i  flag.

       When a query is received, dhcrelay forwards it to the list
       of DHCP servers specified on the command  line.    When  a
       reply  is received, it is broadcast or unicast on the net
       work from whence the original request came.

       It is possible to specify a set  of  interfaces  on  which
       dhcrelay  will  listen,  so  that if dhcrelay is connected
       through one interface to a network on which  there  is  no
       DHCP  server,  but  is connected on another interface to a
       network on which there is a DHCP server, it will not relay
       DHCP  and  BOOTP  requests  from  the network on which the
       server exists to that server.   This is an imperfect solu
       tion.

COMMAND LINE
       The  names  of the network interfaces that dhcrelay should
       attempt to configure may be specified on the command  line
       using  the -i option.  If no interface names are specified
       on the command line dhcrelay  will  identify  all  network
       interfaces, elimininating non-broadcast interfaces if pos
       sible, and attempt to configure each interface.

       If dhcrelay should listen and transmit  on  a  port  other
       than  the  standard  (port  67), the -p flag may used.  It
       should be followed by the udp port  number  that  dhcrelay
       should use.  This is mostly useful for debugging purposes.

       Dhcrelay will normally run in the foreground until it  has
       configured  an  interface, and then will revert to running
       in the background.  To run force dhcrelay to always run as
       a  foreground  process,  the  -d flag should be specified.
       This is useful when running dhcrelay under a debugger,  or
       when running it out of inittab on System V systems.

       Dhcrelay  will normally print its network configuration on
       startup.  This can be annoying in a system startup  script

       - to disable this behaviour, specify the -q flag.

       The  name  of  at  least one DHCP server to which DHCP and
       BOOTP requests should be relayed must be specified on  the
       command line.

SEE ALSO
       dhclient(8) dhcpd(8) RFC2132, RFC2131. 

AUTHOR
       dhcrelay(8)  has  been  written  for the Internet Software
       Consortium by Ted Lemon lt;mellon@fugue.com in  cooperation
       with  Vixie Enterprises.  To learn more about the Internet
       Software Consortium, see http://www.vix.com/isc.  To learn
       more about Vixie Enterprises, see http://www.vix.com.