ypbind(1M) System Administration Commands ypbind(1M)NAMEypbind - 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). Administrative 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 service. 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 information that lets all NIS client processes on a node com‐
municate with some NIS server process. ypbind must run on every machine
which has NIS client processes. The NIS server may or may not be run‐
ning 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
the /etc/hosts file along with their IP addresses. Once a domain is
bound by ypbind, that same binding 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 process
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 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
/etc/inet/hosts
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Availability │SUNWnisu │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOsvcs(1), ypcat(1), ypmatch(1), ypwhich(1), ifconfig(1M), rpc.nisd(1M),
svcadm(1M), ypinit(1M), ypset(1M), ypclnt(3NSL), hosts(4), ypfiles(4),
attributes(5), smf(5)NOTESypbind 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.
SunOS 5.10 17 Aug 2006 ypbind(1M)
