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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
          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>



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