# rarpd(8)

    NAME
         rarpd - reverse address resolution protocol daemon

    SYNOPSIS
         rarpd [-d[level]] network-name ...

    DESCRIPTION
         Rarpd listens on the given networks  for  broadcast  packets  asking  for
         reverse address resolution.  These packets are sent by hosts at boot time
         to find out their IP address.  Rarpd looks  up  the  six  octet  ethernet
         number  in  the  /etc/ethers  file  finding  a  host  name.  This name is
         translated to the IP address of the host by a DNS lookup.  The IP address
         is then sent to the host.

         Under Minix the program forks as needed to  give  each  network  its  own
         server.   Under  Minix-vmd  all  networks are handled in the same program
         using async I/O.

      Private Ethernet Addresses
         For VU practical work, where students have to create their own  IP  stack
         starting at the bottom with RARP, this implementation recognizes Ethernet
         addresses starting with octet 0x76 as special.  The next octet is used as
         a  additional  host  number  and  the  next and last four octets as an IP
         address that this Ethernet address is additional for.  The IP address  is
         translated  back  to  a name, and the first component of that name gets a
         dash and the additional host number added to it.  That hostname  is  then
         looked up and its IP address returned in a RARP reply.  Example:

              76:3:c0:a8:e7:fa        Additional 3, IP 192.168.231.250

              flotsam.example.com     Reverse lookup on 192.168.231.250

              flotsam-3.example.com   Splicing in additional number

              192.168.231.42          Forward lookup

         In this example a RARP query for 76:3:c0:a8:e7:fa gets 192.168.231.42  as
         reply.

    OPTIONS

         -d[level]
              Turns on debugging messages at the given level, by  default  1.   At
              level  1  you will be shown what answers are sent, and at level 2 or
              higher you will be told about queries from unknown hosts or host  on
              the  wrong  network.   The debug level can also be increased by 1 at
              runtime by sending signal SIGUSR1 or turned  off  (set  to  0)  with
              SIGUSR2.

    SEE ALSO
         ifconfig(8), ethers(5), hosts(5), inet(8), boot(8),  dhcpd(8),  irdpd(8),
         inetd(8), nonamed(8).

    NOTES
         A "network name" is the device name of the IP device of a  network,  i.e.
         ip0, ip1, ...

         The RARP protocol has gone out of fashion in favour of DHCP.

    AUTHOR
         Kees J. Bot (kjb@cs.vu.nl)