RPC.YPXFRD(8)		       Reference Manual			 RPC.YPXFRD(8)



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  mes-
	      sages 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 possi-
	      ble to have a router filter packets to the NIS ports.  This  can
	      restricted the access to the NIS server from hosts on the Inter-
	      net.

       --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
       /var/yp/securenets or the tcp wrapper.  If the host is allowed to  con-
       nect   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.colum-
       bia.edu>
       Linux Implementation: Thorsten Kukuk <kukuk@suse.de>



YP Server			  August 2001			 RPC.YPXFRD(8)