ypbind(1M)

NAME

     ypbind - NIS binder process

SYNOPSIS

     /usr/lib/netsvc/yp/ypbind [-broadcast | -ypset | -ypsetme]

DESCRIPTION

     NIS provides a simple network lookup service  consisting  of
     databases  and  processes.  The  databases are stored at the
     machine that runs an NIS server  process.  The  programmatic
     interface  to NIS is described in ypclnt(3NSL).  Administra-
     tive tools are  described  in  ypinit(1M),  ypwhich(1),  and
     ypset(1M).  Tools  to  see  the  contents  of  NIS  maps are
     described in ypcat(1), and ypmatch(1).

     ypbind is a daemon  process  that  is  activated  at  system
     startup  time  from  the startup script /etc/init.d/rpc.  By
     default, it is invoked as ypbind -broadcast. ypbind runs  on
     all  client  machines  that  are  set  up  to  use  NIS. See
     sysidtool(1M).  The function of ypbind is to remember infor-
     mation that lets all NIS client processes on a node communi-
     cate with some NIS server process. ypbind must run on  every
     machine  which has NIS client processes.  The NIS server may
     or may not be running on the same node, but must be  running
     somewhere on the network. If the NIS server is a NIS+ server
     in NIS (YP) compatibility mode, see the NOTES section of the
     ypfiles(4)man page for more information.

     The information ypbind remembers is called a binding  -  the
     association  of a domain name with a NIS server. The process
     of binding is driven by client requests.
      As a request for  an unbound domain comes  in,  if  started
     with  the  -broadcast option, the ypbind process  broadcasts
     on the net trying to find an NIS  server,  either  a  ypserv
     process  serving  the  domain or an rpc.nisd process in "YP-
     compatibility mode" serving NIS+  directory  with  name  the
     same  as  (case sensitive) the domain in the client request.
     Since the binding is  established  by  broadcasting,   there
     must  be  at  least  one  NIS  server on the net. If started
     without the -broadcast option, ypbind process steps  through
     the  list  of  NIS servers that was created by ypinit -c for
     the requested domain. There must be an NIS server process on
     at  least  one of the hosts in the NIS servers file. All the
     hosts in the NIS servers file must be listed in  either  the
     /etc/hosts  or  /etc/inet/ipnodes  files along with their IP
     addresses. Once a domain is bound by ypbind, that same bind-
     ing is given to every client process on the node. The ypbind
     process on the local node or a remote node  may  be  queried
     for  the  binding  of  a  particular  domain  by  using  the
     ypwhich(1) command.

     If ypbind is unable to speak to the NIS server process it is
     bound  to,  it marks the domain as unbound, tells the client
     process that the domain is unbound, and tries  to  bind  the
     domain  once  again. Requests received for an unbound domain
     will wait until the requested domain is bound. In general, a
     bound  domain is marked as unbound when the node running the
     NIS server crashes or  gets  overloaded.  In  such  a  case,
     ypbind will try to bind to another NIS server using the pro-
     cess described above.ypbind also accepts requests to set its
     binding  for  a  particular  domain.  The request is usually
     generated by the ypset(1M) command. In order  for  ypset  to
     work,  ypbind must have been invoked with flags -ypset or  -
     ypsetme.

OPTIONS

     - broadcast
           Send a broadcast datagram using UDP/IP  that  requests
           the  information  needed  to  bind  to  a specific NIS
           server. This option is analogous  to  ypbind  with  no
           options in earlier Sun releases and is recommended for
           ease of use.

     -ypset
           Allow users from any  remote  machine  to  change  the
           binding  by means of the ypset command. By default, no
           one can change the binding. This option is insecure.

     -ypsetme
           Only allow root on the local  machine  to  change  the
           binding to a desired server by means of the ypset com-
           mand.  ypbind can verify the caller is indeed  a  root
           user  by  accepting such requests only on the loopback
           transport. By default, no external process can  change
           the binding.

FILES

      /var/yp/binding/ypdomain/ypservers

     /etc/inet/hosts

     /etc/inet/ipnodes

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWnisu                    |
    |_____________________________|_____________________________|

SEE ALSO

     ypcat(1),     ypmatch(1),     ypwhich(1),      ifconfig(1M),
     rpc.nisd(1M), ypinit(1M), ypset(1M), ypclnt(3NSL), hosts(4),
     ipnodes(4), ypfiles(4), attributes(5)

NOTES

     ypbind supports multiple domains. The   ypbind  process  can
     maintain  bindings to several domains and their servers, the
     default domain is the one specified by  the   domainname(1M)
     command at startup time.

     The -broadcast option works only on the UDP transport. It is
     insecure  since  it  trusts  "any"  machine  on the net that
     responds to the broadcast request and poses itself as an NIS
     server.