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 store 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  pro-
       tocol, so that there is no need for building a new map.

       rpc.ypxfrd  could be started by inetd. But since it starts
       very  slow,  it  should  be  started  with   ypserv   form
       /etc/init.d/nis.

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
       then  ypserv.   At  first, rpc.ypxfrd will check a request
       from an address with /var/yp/securenets or the  tcp  wrap-
       per.   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 impli-
       mentation 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 sensi-
       tive 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
       lt;wpaul@ctr.columbia.edu

       Linux  Implementation:  Thorsten  Kukuk  <kukuk@uni-pader-
       born.de>