ypbindSection: Maintenance Commands (8)
Updated: May 1999
Return to Main Contents
NAMEypbind - NIS binding process
SYNOPSISypbind [ -c ] [ -d|-debug ] [ -broadcast ] [ -broken-server ] [ -ypset ] [ -ypsetme ] [ -no-ping ] [ -p port ][ -f configfile ]
DESCRIPTIONypbind finds the server for NIS domains and maintains the NIS binding information. The client (normaly the NIS routines in the standard C library) could get the information over RPC from ypbind or read the binding files. The binding files resides in the directory /var/yp/binding and are conventionally named [domainname].[version]. The supported versions are 1 and 2. There could be serveral such files since it is possible for an NIS client to be bound to more then one domain.
After a binding has been established, ypbind will send YPPROC_DOMAIN requests to the current NIS server at 20 seconds intervals. If it doesn't get an response or the NIS server tells that he doesn't has this domain any longer, ypbind will search a new NIS server. All 15 minutes ypbind will check, if the current NIS server is the fastest. If it find a server which answers faster, it will switch to this server. You could tell ypbind to use network broadcasts to find a new server, what is insecure, or you could give it a list of known, secure servers. In this case ypbind will send a ping to all server and binds to first one which answers.
Unless the option -debug is used, ypbind detaches itself from the controlling terminal and puts itself into background. ypbind uses for logging errors and warnings. At startup or when receiving signal SIGHUP, ypbind parses the file /etc/yp.conf and tries to use the entries for its initial binding. Valid entries are
domain nisdomain server hostname
domain nisdomain broadcast
A broadcast entry in the configuration file will overwrite a ypserver/server entry and a ypserver/server entry broadcast. If all given server are down, ypbind will not switch to use broadcast. ypbind will try at first /etc/hosts and then DNS for resolving the hosts names from /etc/yp.conf. If ypbind couldn't reconfigure the search order, it will use only DNS. If DNS isn't available, you could only use IP-addresses in /etc/hosts. ypbind could only reconfigure the search order with glibc 2.x. If the -broadcast option is specified, ypbind will ignore the configuration file. If the file does not exist or if there are no valid entries, ypbind exit.
This ypbind is a special version which uses pthreads. It will start 2 more threads. The master process services RPC requests asking for binding info. The first thread initializes the binding and checks it periodically. Upon failure, the binding is invalidated and the process tries again to find a valid server. The second thread will handle all the signals.
NOTESBinding to multiple domains is tested and works. Load sharing between multiple servers for a single domain is not supported. ypbind will always try to bind a domain to a server. If there is no valid server in the list or answers to a broadcast, the domain is unbounded.
SEE ALSOsyslog(3), domainname(1), ypwhich(1), ypserv(8), ypset(8)
AUTHORypbind-mt was written by Thorsten Kukuk <email@example.com>.
This document was created by man2html, using the manual pages.
Time: 18:10:30 GMT, February 23, 2024