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
ypbindto 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.