rarpd(8)


NAME

   rarpd - Reverse Address Resolution Protocol (RARP) daemon

SYNOPSIS

   rarpd [-aAvode] [-b bootdir] [interface]

DESCRIPTION

   Rarpd  is  a  daemon  which responds to RARP requests.  RARP is used by
   some machines at boot time to discover their IP address.  They  provide
   their  Ethernet  address and rarpd responds with their IP address if it
   finds it in the  ethers  database  (either  /etc/ethers  file  or  NIS+
   lookup) and using DNS lookup if the ethers database contains a hostname
   and not an IP address.  In addition, /etc/hosts  will  provide  further
   means of pairing an IP address to a hostname, in the standard fashion.

   By  default  rarpd  also checks if a bootable image, of a name starting
   with the IP address in hexadecimal upper-case letters,  is  present  in
   the  TFTP  boot  directory  before it decides whether to respond to the
   RARP  request.   The  comparison  involves  exactly  the  first   eight
   characters,  and ignores any additional character.  A file name shorter
   than  eight  characters  in   length   is   unsuccessful.    Typically,
   192.168.0.122 would correspond to an image named like C0A8007A.SUN.

   The optional argument interface restricts the daemon instance to access
   only the indicated network interface. Only a single name is possible.

OPTIONS

   -a     Do not bind to a single interface, but listen at all  configured
          interfaces.

   -A     Respond to reverse requests received as ARP-packets, in addition
          to those  protocol  conformant  requests  transmitted  as  RARP-
          packets.  See the notes for the background.

   -v     Tell the user what is going on by being verbose.

   -d     Debugging  mode.  Do  not detach from the tty. This also implies
          verbose mode.

   -e     Skip the check for bootable images in the TFTP  boot  directory.
          In  the  absence of this switch, even if the Ethernet address is
          present in the ethers database, the lack of a bootable image for
          the  resolved  IP  will  make  rarpd  refrain from responding to
          requests for this particular address.

   -o     Accept offlink packages on the active interfaces.

   -b bootdir
          Access bootdir instead of the default /tftpboot as the TFTP boot
          directory for bootable image checks.

OBSOLETES

   This daemon rarpd obsoletes kernel rarp daemon present in Linux kernels
   up to 2.2 which was controlled by the rarp(8) command.

SIGNALS

   SIGHUP Renew the internal address list, which  records  IPv4  addresses
          available  at each active network interface. The restriction set
          by the command line argument interface is still in effect, if in
          use.

NOTES

   The  protocol  stipulates  that  Reverse  Requests be broadcast as RARP
   packets, using a protocol number different from  that  in  use  by  ARP
   packets.   However, there has been an obsolete practice of transmitting
   also Reverse Requests in ARP packets, and some old clients may still be
   around  that  adhere  to  that  practice.  To activate support for such
   obsolete client  hosts,  the  switch  -A  must  be  applied.   Observe,
   however,  that  only  ARP-packaged ARPOP_RREQUEST messages are added to
   the servers responsabilities with the use of this option, and that  the
   replies to these will be sent as ARP-packaged ARPOP_RREPLY messages.

FILES

   /etc/ethers
          Text data base of ethernet to host pairs.

   /etc/hosts
          Text lookup table of host names.

   /etc/nsswitch.conf
          Name resolver configuration.

   /tftpboot
          Default boot directory.

   /tftpboot/HEXADDR
          Typical name of a boot image.  It is a file or a directory.  The
          IPv4 address is  translated  as  eight  upper-case,  hexadecimal
          digits  in the mandatory part HEXADDR.  Optionally, the name may
          be extended with an arbitrary suffix.

SEE ALSO

   ethers(5), hosts(5), nsswitch.conf(5)

AUTHORS

   Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   Jakub Jelinek, <jakub@redhat.com>





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