NAME

       dhcp-helper - A DHCP/BOOTP relay agent.

SYNOPSIS

       dhcp-helper [OPTION]...

DESCRIPTION

       dhcp-helper  is  a DHCP and BOOTP relay agent. It listens for DHCP and BOOTP broadcasts on
       directly connected subnets and relays them to DHCP or BOOTP  servers  elsewhere.  It  also
       relays  replies from the remote servers back to partially configured hosts. Once hosts are
       fully configured they can communicate directly with their servers and no longer  need  the
       services of a relay.

OPTIONS

       The  only  required  option  is  at least one DHCP server to relay to. The simplest way to
       configure dhcp-helper on a router is just to give the interface to the network  containing
       the  DHCP  server  with  a -b option. All the other interfaces present on the machine will
       then accept DHCP requests. On a machine which does not have an interface  on  the  network
       containing the DHCP server, use a -s option instead.

       -s <server>
              Specify  a  DHCP  or BOOTP server to relay to. The server may be given as a machine
              name or dotted-quad IP address. More than one server may be specified.

       -b <interface>
              Relay to a DHCP or BOOTP server using broadcast via  <interface>.  This  eliminates
              the  need  to give a server address. <interface> is automatically added to the list
              of interfaces which will not receive DHCP requests.

       -i <interface>
              Specify which local interfaces to listen on for DHCP/BOOTP  broadcasts.  If  no  -i
              flags  are  given  all  interfaces  are used except those specified by -e flags and
              those specified by -b flags.

       -e <interface>
              Specify which local interfaces to exclude.

       -p     Use alternative ports (1067/1068) for the DHCP client and server.

       -v     Report the software release version and copyright information.

       -d     Debug mode, do not change UID, write a pid-file or go into the background.

       -r <file>
              Specify an alternate path for dhcp-helper to record  its  process-id  in.  Normally
              /var/run/dhcp-helper.pid.

       -u <username>
              Specify  the userid to which dhcp-helper will change after startup. The daemon must
              normally be started as root, but it will drop root  priviledges  after  startup  by
              changing  id  to another user. Normally this user is "nobody" but that can be over-
              ridden with this switch.

NOTES

       Dhcp-helper requires a 2.2 or later Linux kernel. The "Linux packet  filter"  and  "packet
       socket"  facilities  are  not required, which is the chief advantage of this software over
       the ISC DHCP relay daemon.

AUTHOR

       This manual page was written by Simon Kelley <simon@thekelleys.org.uk>.

                                                                                   DHCP-HELPER(8)