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>