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ypbind(8) ypbind(8)
NAME
ypbind - NIS binding process
SYNOPSIS
ypbind [ -c ] [ -d|-debug ] [ -broadcast ] [ -broken-server ] [ -ypset
] [ -ypsetme ] [ -no-ping ] [ -f configfile ]
ypbind --version
DESCRIPTION
ypbind 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 several 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 con-
trolling terminal and puts itself into background. ypbind uses sys-
log(3) 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
Use server hostname for the domain nisdomain. You could have
more then one entry of this type for a single domain.
domain nisdomain broadcast
Use broadcast on the local net for domain nisdomain.
ypserver hostname
Use server server for the local domain.
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 speci-
fied, 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.
OPTIONS
-broadcast
Send a broadcast to request the information needed to bind to a
specific NIS server. With this option, /etc/yp.conf will be
ignored.
-ypset Allow root from any remote machine to change the binding for a
domain via the ypset(8) command. By default, no one can change
the binding. This option is really insecure. If you change a
binding for a domain, all the current known servers for this
domain will be forgotten. If the new server goes down, ypbind
will use the old searchlist.
-ypsetme
The same as -ypset, but only root on the local machine is
allowed to chang the binding. Such requests are only allowd
from loopback.
-c ypbind only checks if the config file has syntax errors and
exits.
-debug starts ypbind in debug mode. ypbind will not put itself into
background, and error messages and debug output are written to
standard error.
-broken-server
lets ypbind accept answers from servers running on an illegal
port number. This should usually be avoided, but is required by
some ypserv(8) versions.
-no-ping
ypbind will not check if the binding is alive. This option is
for use with dialup connections to prevent ypbind from keeping
the connection unnessecarily open or causing autodials.
-f configfile
ypbind will use configfile and not /etc/yp.conf
--version
Prints the version number
NOTES
Binding 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.
FILES
/etc/yp.conf
configuration file.
/var/yp/binding/[domainname].[version]
binding file containing information about each NIS domain.
/var/run/ypbind.pid
contains the process id of the currently running ypbind master
process.
SEE ALSO
syslog(3), domainname(1), ypdomainname(8), ypwhich(1), ypserv(8),
ypset(8)
AUTHOR
ypbind-mt was written by Thorsten Kukuk .
ypbind-mt Version 1.17.2 April 2002 ypbind(8)
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