Manual Pages for UNIX Operating System command usage for man ypbind

System Administration Commands                         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 svc:/network/nis/client:default ser-
     vice. 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.


     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, that is, a ypserv process serving the
     domain with a name the same as (case sensitive) the name  of
     the domain in the client request. Since the binding is esta-
     blished 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. It is recommended that you list
     each of these NIS servers by name and numeric IP address  in
     /etc/hosts.  Though  the  practice  is  not recommended, NIS
     allows you to list servers by numeric address only,  bypass-
     ing  /etc/hosts. In such a configuration, ypwhich(1) returns
     a numeric address instead of a name.


     Once a domain is bound by ypbind, that same binding is given
     to  every  client process on the node. The ypbind process on



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System Administration Commands                         ypbind(1M)



     the local node or a remote node may be queried for the bind-
     ing 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  bind-
         ing  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 bind-
         ing  to  a desired server by means of the ypset command.
         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

         Lists the servers to which the NIS client is allowed  to
         bind.


     /etc/inet/hosts




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System Administration Commands                         ypbind(1M)



         File in which it is  recommended  that  NIS  servers  be
         listed.


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



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | system/network/nis          |
    |_____________________________|_____________________________|


SEE ALSO
     svcs(1),  ypcat(1),  ypmatch(1),  ypwhich(1),  ifconfig(1M),
     svcadm(1M),  ypinit(1M),  ypset(1M), ypclnt(3NSL), hosts(4),
     ypfiles(4), attributes(5), smf(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.


     The ypbind service is  managed  by  the  service  management
     facility, smf(5), under the service identifier:

       svc:/network/nis/client:default




     Administrative actions on this service,  such  as  enabling,
     disabling,  or  requesting  restart,  can be performed using
     svcadm(1M). The service's status can be  queried  using  the
     svcs(1) command.








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