is a fundamental part of the network
information system called YP. This server provides information from YP maps to
the YP clients on the network.
A YP map is stored on the server as a Berkeley database. A number of YP maps are
grouped together in a domain. ypserv
the domains it serves by looking for a directory with the domain name in
YP hasn't been known for high security through the years. In recent years
security has improved by restricting access to the server. In SunOS 4.1 has a
new file occurred named /var/yp/securenet
contains networks the server can assume is secure. For information about the
file format, see
Before the author of this server had seen
implemented. This file format makes it possible to allow and deny hosts and
networks access to the server. This file can have any name since it's given by
the argument to -a
(use full path).
If a host isn't secure all queries to the server will result in a YP_NODOM
If the file /var/yp/ypserv.log
exists then messages
will be written to the file.
If a directory named the same as the system domainname exists in
(i.e., the domainname is
“foo” and the directory /var/yp/foo
exists), then ypserv
will be automatically
started at boot time.
On receipt of a hangup signal,
will reopen the log file and reread its
configuration, including both the map files and the
The options are as follows:
- Allow ypserv to answer old YP
version 1 requests.
- Don't use /var/yp/securenet.
Use another file with a different file format. For further information see
- Use Internet Domain Name System. If a query to map
“hosts.byname” or “hosts.byaddr” fails, make a
DNS query and return the result if successful. Alternately, if these maps
were built on the YP master using makedbm
-b then DNS queries will be done without
needing to specify -d.
- Terminate the server after processing
Mats O Jansson