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ypserv(8)                 BSD System Manager's Manual                ypserv(8)


     ypserv -- YP server daemon


     ypserv [-1] [-a aclfile] [-d] [-x]


     Ypserv is a fundamental part of the network information system called YP.
     This server provides information from YP maps to the YP clients on the

     A YP map is stored on the server as a db(3) database. A number of YP maps
     is grouped together in a domain.  Ypserv determines the domains it serves
     by looking for a directory with the domain name in /var/yp.

     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 occured named /var/yp/securenet.  It contains networks the
     server can assume is secure. For information about file format see

     Before the author of this server had seen securenet(5) another format was
     implemented ypserv.acl(5).  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).

     The file used can be reread by sending a SIGHUP to ypserv. The process
     pid can be found in the file /var/run/

     If a host isn't secure all queries to the server will result in a
     YP_NODOM result.

     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 /var/yp/
     (ie. the domainname is foo and directory /var/yp/foo exists), then ypserv
     will be automatically started at boot time.

     The options are as follows:

     -1      Allow ypserv to answer old YP version 1 requests.

     -a aclfile
             Don't use /var/yp/securenet.  Use another file with another file
             format. For futher information see man page for ypserv.acl.

     -d      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 mas-
             ter using makedbm -b then DNS queries will be done without need-
             ing to specify -d.

     -x      Terminate the server after processing aclfile or




     yp(8), ypserv.acl(5), securenet(5), ypbind(1)


     Mats O Jansson <>

BSD                              June 27, 1994                             BSD

Mac OS X 10.8 - Generated Wed Sep 5 05:13:46 CDT 2012
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