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 3 the program forks as needed to give each net-
work its own server. Under Minix-vmd all networks are han-
dled 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 imple-
mentation 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 com-
ponent 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)