.\"	$NetBSD: ypbind.8,v 1.16 2005/02/26 16:19:08 wiz Exp $
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.Dd February 26, 2005
.Dt YPBIND 8
.Os
.Sh NAME
.Nm ypbind
.Nd create and maintain a binding to a NIS server
.Sh SYNOPSIS
.Nm
.Op Fl broadcast
.Op Fl insecure
.Op Fl ypset
.Op Fl ypsetme
.Sh DESCRIPTION
.Nm
finds the server for a particular
.Tn NIS
domain and stores information about it
in a
.Dq binding file .
This binding information includes the IP address of the server associated with
that particular domain and which port the server is using.
This information is stored in the directory
.Pa /var/yp/binding
in a file named with the convention
.Pa \*[Lt]domain\*[Gt].version ,
where
.Aq domain
is the relevant domain.
The
.Tn NIS
system only supplies information on version 2.
.Pp
If
.Nm
is started without the
.Fl broadcast
option,
.Nm
steps through the list of
.Tn NIS
servers specified in
.Pa /var/yp/binding/\*[Lt]domain\*[Gt].ypservers
and contacts each in turn attempting to bind to that server.
It is strongly recommended that these hosts are in the local
hosts file, and that hosts are looked up in local files before
the
.Tn NIS
hosts map.
.Pp
If
.Nm
is started with the
.Fl broadcast
option, or if
.Pa /var/yp/binding/\*[Lt]domain\*[Gt].ypservers
does not exist,
.Nm
broadcasts to find a process willing to serve maps for the
client's domain.
.Pp
Once a binding is established,
.Nm
maintains this binding by periodically communicating with the server to which
it is bound.
If the binding is somehow lost, e.g by server reboot,
.Nm
marks the domain as unbound and attempts to re-establish the binding.
When the binding is once again successful,
.Nm
marks the domain as bound and resumes its periodic check.
.Pp
The options are as follows:
.Bl -tag -width "-broadcast"
.It Fl broadcast
sends a broadcast requesting a
.Tn NIS
server to which to bind.
.It Fl insecure
do not require that the server is running on a reserved port.
This may be necessary when connecting to
.Tn SunOS 3.x
or
.Tn ULTRIX
.Tn NIS
servers.
.It Fl ypset
.Xr ypset 8
may be used to change the server to which a domain is bound.
.It Fl ypsetme
.Xr ypset 8
may be used only from this machine to change the server
to which a domain is bound.
.El
.Pp
The
.Fl broadcast
.Fl ypset ,
and
.Fl ypsetme ,
options are inherently insecure and should be avoided.
.Sh FILES
.Pa /var/yp/binding/\*[Lt]domain\*[Gt].version
- binding file for \*[Lt]domain\*[Gt].
.Pa /var/yp/binding/\*[Lt]domain\*[Gt].ypservers
- explicit list of servers to bind to for \*[Lt]domain\*[Gt].
.Sh DIAGNOSTICS
Messages are send to syslog daemon using facility LOG_DAEMON.
.Sh SEE ALSO
.Xr domainname 1 ,
.Xr ypcat 1 ,
.Xr ypmatch 1 ,
.Xr ypwhich 1 ,
.Xr nis 8 ,
.Xr yppoll 8 ,
.Xr ypset 8
.Sh AUTHORS
This version of
.Nm
was originally implemented by Theo de Raadt.
The ypservers support was implemented by Luke Mewburn.