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       dhcp-helper - A DHCP/BOOTP relay agent.


       dhcp-helper [OPTION]...


       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.


       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

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

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

       -v     Report the software release version and copyright information.

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

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

       -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.


       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.


       This manual page was written by Simon Kelley <>.