NAME
ypbind —
create and maintain a binding
to a NIS server
SYNOPSIS
ypbind |
[-broadcast]
[-insecure]
[-ypset]
[-ypsetme] |
DESCRIPTION
ypbind finds the server for a particular NIS domain and stores
information about it in a “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
/var/yp/binding in a file named with the
convention
<domain>.version, where
⟨domain⟩ is the relevant domain. The NIS system only supplies
information on version 2.
If
ypbind is started without the
-broadcast
option,
ypbind steps through the list of NIS servers
specified in
/var/yp/binding/<domain>.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 NIS hosts map.
If
ypbind is started with the
-broadcast
option, or if
/var/yp/binding/<domain>.ypservers does
not exist,
ypbind broadcasts to find a process willing to
serve maps for the client's domain.
Once a binding is established,
ypbind 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,
ypbind marks
the domain as unbound and attempts to re-establish the binding. If a binding
cannot be re-established within 60 seconds,
ypbind backs off
exponentially to trying only once per hour.
The options are as follows:
-
-
- -broadcast
- sends a broadcast requesting a NIS server to which to
bind.
-
-
- -insecure
- do not require that the server is running on a reserved
port. This may be necessary when connecting to SunOS 3.x or ULTRIX NIS
servers.
-
-
- -ypset
- ypset(8) may
be used from anywhere to change the server to which a domain is
bound.
-
-
- -ypsetme
- ypset(8) may
be used only from this machine to change the server to which a domain is
bound.
The
-broadcast,
-ypset, and
-ypsetme options are inherently insecure and should be
avoided.
SIGNALS
ypbind responds to the following signals:
HUP
- causes ypbind to immediately retry any
unbound domains that are currently in exponential backoff. Use this to
resume immediately after a long network outage is resolved.
FILES
/var/yp/binding/<domain>.version - binding file for
<domain>.
/var/yp/binding/<domain>.ypservers -
explicit list of servers to bind to for <domain>.
DIAGNOSTICS
Messages are sent to
syslogd(8)
using the
LOG_DAEMON
facility.
SEE ALSO
domainname(1),
ypcat(1),
ypmatch(1),
ypwhich(1),
nis(8),
yppoll(8),
ypset(8)
AUTHORS
This version of
ypbind was originally implemented by
Theo de Raadt. The ypservers support was implemented
by
Luke Mewburn.