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 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
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
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
<wpaul@ctr.columbia.edu>
Linux Implementation: Thorsten Kukuk <kukuk@suse.de>
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