ypbind



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/bind-
       ing 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 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.



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 <kukuk@suse.de>.



ypbind-mt Version 1.17.2          April 2002                         ypbind(8)

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