NAME

       rpc.ypxfrd - NIS map transfer server

SYNOPSIS

       /usr/sbin/rpc.ypxfrd [ -d path ] [ -p port ] [ --debug ]
       /usr/sbin/rpc.ypxfrd --version

DESCRIPTION

       rpc.ypxfrd  is  used  for speed up the transfer of very large NIS maps from a NIS master to the NIS slave
       server. If a  NIS slave server receives a message that there is a  new  map,  it  will  start  ypxfr  for
       transfering the new map.  ypxfr will read the contents of a map from the master server using the yp_all()
       function. This process can take several minutes when there are very large maps which have to be stored by
       the database library.

       The  rpc.ypxfrd  server  speeds  up the transfer process by allowing NIS slave servers to simply copy the
       master server's map files rather than building their own from scratch.  rpc.ypxfrd uses an RPC-based file
       transfer protocol, so that there is no need for building a new map.

       rpc.ypxfrd could be started by inetd. But since it starts very slowly, it should be started after  ypserv
       from /etc/init.d/ypxfrd.

OPTIONS

       --debug
              Causes  the  server to run in debugging mode. In debug mode, the server does not background itself
              and prints extra status messages to stderr for each request that it revceives.

       -d directory
              rpc.ypxfrd is using this directory instead of /var/yp

       -p port
              rpc.ypxfrd will bind itself to this port, which makes it possible to have a router filter  packets
              to the NIS ports. This can restricted the access to the NIS server from hosts on the Internet.

       --version
              Prints the version number

SECURITY

       rpc.ypxfrd  uses  the  same  functions  for checking a host as ypserv.  At first, rpc.ypxfrd will check a
       request from an address with /etc/ypserv.securenets.  If the host is allowed to connect  to  the  server,
       rpc.ypxfrd  will  uses  the  rules from /etc/ypserv.conf to check the requested map. If a mapname doesn't
       match a rule, rpc.ypxfrd will look for the YP_SECURE key in the map. If it exists, rpc.ypxfrd  will  only
       allow requests on a reserved port.

FILES

       /etc/ypserv.conf /var/yp/securenets

SEE ALSO

       ypserv(8), makedbm(8), yppush(8), ypxfr(8)

BUGS

       The  FreeBSD  ypxfrd  protocol  is  not  compatible  with  that  used  by  SunOS. This is unfortunate but
       unavoidable: Sun's protocol is not freely available, and even if it were it would probably not be  useful
       since  the  SunOS  NIS v2 implimentation uses the original ndbm package for its map databases whereas the
       other implimentation uses GNU DBM or Berkeley DB. These packages  uses  vastly  different  file  formats.
       Furthermore,  ndbm  and gdbm are byte-order sensitive and not very smart about it, meaning that a gdbm or
       ndbm database created on a big endian system can't be read on a little endian system. The FreeBSD  ypxfrd
       protocol  checks,  if both, master and slave, uses the same database packages and, if necessary, the byte
       order of the system.

AUTHOR

       ypxfrd protocol and FreeBSD Implementation: Bill Paul <wpaul@ctr.columbia.edu>
       Linux Implementation: Thorsten Kukuk <kukuk@suse.de>

YP Server                                          August 2001                                     RPC.YPXFRD(8)