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 ypserv(1M)							  ypserv(1M)




 NAME
      ypserv, ypbind, ypxfrd - Network Information Service (NIS) server,
      binder, and transfer processes

 SYNOPSIS
      /usr/lib/netsvc/yp/ypserv [-l log_file]

      /usr/lib/netsvc/yp/ypbind [-l log_file] [-s] [-ypset|-ypsetme]

      /usr/sbin/ypxfrd

    Remarks
      The Network Information Service (NIS) was formerly known as Yellow
      Pages (YP).  The functionality remains the same; only the name has
      changed.

 DESCRIPTION
      The Network Information Service (NIS) provides a simple network lookup
      service consisting of databases and processes.  The databases are
      files in a directory tree rooted at /var/yp (see ypfiles(4)).  The
      processes are /usr/lib/netsvc/yp/ypserv, the NIS database lookup
      server, and /usr/lib/netsvc/yp/ypbind, the NIS binder.  Both ypserv
      and ypbind are daemon processes activated at system startup time when
      the NIS_MASTER_SERVER or NIS_SLAVE_SERVER variable is set to 1, for
      ypserv, and the NIS_CLIENT variable is set to 1, for ypbind, in the
      /etc/rc.config.d/namesvrs file.

      The NIS programmatic interface is described in ypclnt(3C).
      Administrative tools are described in ypwhich(1), yppoll(1M),
      yppush(1M), ypset(1M) and ypxfr(1M).  Tools to see the contents of NIS
      maps (databases) are described in ypcat(1) and ypmatch(1).  Database
      generation and maintenance tools are described in makedbm(1M),
      ypinit(1M), and ypmake(1M).  The command to set or show the default
      NIS domain is domainname(1).

      ypxfrd transfers entire NIS maps in an efficient manner.	For systems
      that use this daemon, map transfers will be faster, depending on the
      map.  ypxfrd should be run on a server running HP-UX release 10.0.
      ypxfr (see ypxfr(1M)) will attempt to use ypxfrd first.  If that
      fails, it will use the older transfer method.  The ypxfrd daemon is
      activated at system startup time when the NIS_MASTER_SERVER or
      NIS_SLAVE_SERVER variable is set to 1 in the /etc/rc.config.d/namesvrs
      file.

      The ypserv daemon's primary function is to look up information in its
      local collection of NIS maps.  It runs only on NIS server machines
      providing data from NIS databases.  Communication to and from ypserv
      is by means of RPC.  Lookup functions are described in ypclnt(3C).

      Four lookup functions perform on a specific map within a NIS domain:
      Match, Get_first, Get_next, and Get_all.	The Match operation matches



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 ypserv(1M)							  ypserv(1M)




      a key to a record in the database and returns its associated value.
      The Get_first operation returns the first key-value pair (record) from
      the map, and Get_next enumerates (sequentially retrieves) the
      remainder of the records.	 Get_all returns all records in the map to
      the requester as the response to a single RPC request.

      Two other functions supply information about the map other than normal
      map entries: Get_order_number and Get_master_name.  The order number
      is the time of last modification of a map.  The master name is the
      host name of the machine on which the master map is stored.  Both
      order number and master name exist in the map as special key-value
      pairs, but the server does not return these through the normal lookup
      functions.  (If you examine the map with makedbm or yppoll (see
      makedbm(1M) or yppoll(1M)), they will be visible.) Other functions are
      used within the NIS system and are not of general interest to NIS
      clients.	They include:

	   Do_you_serve_this_domain?
	   Transfer_map
	   Reinitialize_internal_state

      The ypbind daemon remembers information that lets client processes on
      its machine communicate with a ypserv process.  The ypbind daemon must
      run on every machine using NIS services, both NIS servers and clients.
      The ypserv daemon may or may not be running on a NIS client machine,
      but it must be running somewhere on the network or be available
      through a gateway.

      The information that ypbind remembers is called a binding: the
      association of a NIS domain name with the Internet address of the NIS
      server and the port on that host at which the ypserv process is
      listening for service requests.  This information is cached in the
      directory /var/yp/binding using a filename in the form
      domainname.version.

      Client requests drive the binding process.  As a request for an
      unbound domain comes in, the ypbind process broadcasts on the network
      trying to find a ypserv process serving maps within that NIS domain.
      Since the binding is established by broadcasting, at least one ypserv
      process must exist on every network.  Once a binding is established
      for a client, it is given to subsequent client requests.	Execute
      ypwhich to query the ypbind process (local and remote) for its current
      binding (see ypwhich(1)).

      Bindings are verified before they are given to a client process.	If
      ypbind is unable to transact with the ypserv process it is bound to,
      it marks the domain as unbound, tells the client process that the
      domain is unbound, and tries to bind again.  Requests received for an
      unbound domain fail immediately.	Generally, a bound domain is marked
      as unbound when the node running ypserv crashes or is overloaded.	 In
      such a case, ypbind binds to any NIS server (typically one that is



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 ypserv(1M)							  ypserv(1M)




      less heavily loaded) that is available on the network.

      The ypbind daemon also accepts requests to set its binding for a
      particular domain.  ypset accesses the Set_domain facility; it is for
      unsnarling messes and is not for casual use.

    Options
      ypserv recognizes the following options:

	   -l log_file	  Log diagnostic and error messages to the file,
			  log_file.

			  If ypserv is started without the -l option, ypserv
			  writes its messages to /var/yp/ypserv.log if that
			  file exists.

			  If ypbind is started without the -l option, ypbind
			  writes its messages directly to the system
			  console, /dev/console.

			  Information logged to the file includes the date
			  and time of the message, the host name, the
			  process id and name of the function generating the
			  message, and the message itself.  Note that
			  different services can share a single log file
			  since enough information is included to uniquely
			  identify each message.

      ypbind recognizes the following options:

	   -l log_file	  Log diagnostic and error messages to the file,
			  log_file.  See the description above.

	   -s		  Secure.  When specified, only NIS servers bound to
			  a reserved port are used.  This allows for a
			  slight increase in security in completely
			  controlled environments, where there are no
			  computers operated by untrusted individuals.	It
			  offers no real increase in security.

	   -ypset	  Allow ypset to be used to change the binding (see
			  ypset(1M)).  For maximum security, this option
			  should be used only when debugging the network
			  from a remote machine.

	   -ypsetme	  Allow ypset to be issued from this machine (see
			  ypset(1M)).  Security is based on IP address
			  checking, which can be defeated on networks where
			  untrusted individuals may inject packets.  This
			  option is not recommended.




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 ypserv(1M)							  ypserv(1M)




 AUTHOR
      ypserv, ypbind, and ypxfrd were developed by Sun Microsystems, Inc.

 FILES
      /var/yp/binding/domainname.version These files cache the last
					 successful binding created for the
					 given domain, in order to to speed
					 up the binding process.  When a
					 binding is requested, these files
					 are checked for validity and then
					 used.

      /var/yp/securenets		 This file is read by ypxfrd and
					 ypserv.  It contains a list of IP
					 addresses that these servers will
					 allow a binding to.

      /var/yp/secureservers		 This file is read by ypbind.  It
					 contains a list of IP addresses
					 that ypbind will receive a binding
					 from.

 SEE ALSO
      domainname(1), ypcat(1), ypmatch(1), yppasswd(1), ypwhich(1),
      makedbm(1M), rpcinfo(1M), ypinit(1M), ypmake(1M), yppasswdd(1M),
      yppoll(1M), yppush(1M), ypset(1M), ypxfr(1M), ypclnt(3C),
      yppasswd(3N), ypfiles(4).



























 Hewlett-Packard Company	    - 4 -   HP-UX Release 11i: November 2000