HP-UX Reference (11i v2 04/09) - 1M System Administration Commands N-Z (vol 4)

y
ypserv(1M) ypserv(1M)
Client requests drive the binding process. As a request for an unbound domain comes in, the
ypbind
process broadcasts on the network, if the file
/var/yp/binding/
domain_name /ypservers does not
exist, trying to find a
ypserv process serving maps within that NIS domain. If the binding should be
established by broadcasting, at least one
ypserv process must exist on every network. If the file
/var/yp/binding/
domain_name /ypservers is present, then ypbind will try to bind to one of the
NIS servers in the order of its listing in the file. If
ypbind was unable to bind to any one of the servers
available in the list, it will try establishing a binding by broadcasting. The file,
/var/yp/binding/
domain_name /ypservers, containing the list of NIS servers is created by invok-
ing
ypinit with -c option. (see ypinit(1M)). If
ypbind is invoked with a -broadcast option,
ypbind will try to establish a binding by broadcast immaterial of the availability of the file
/var/yp/binding/
domain_name /ypservers i.e. the option -broadcast overrides the existence
of the file
/var/yp/binding/
domain_name /ypservers. Once a binding is established for a client,
it is given to subsequent client requests. Execute
ypwhich to query the ypbind process (local and
remote) for its current binding (see ypwhich (1)).
Bindings are verified before they are given to a client process. If
ypbind is unable to transact with the
ypserv process it is bound to, it marks the domain as unbound, tells the client process that the domain
is unbound, and tries to bind again. Requests received for an unbound domain fail immediately. Gen-
erally, a bound domain is marked as unbound when the node running
ypserv crashes or is overloaded.
In such a case,
ypbind binds to any NIS server (typically one that is less heavily loaded) that is avail-
able on the network.
The
ypbind daemon also accepts requests to set its binding for a particular domain. ypset accesses the
Set_domain facility; it is for unsnarling messes and is not for casual use.
Options
ypserv recognizes the following options:
-l log_file Log diagnostic and error messages to the file, log_file.
If
ypserv is started without the -l option, ypserv writes its messages to
/var/yp/ypserv.log
if that file exists.
If
ypbind is started without the -l option, ypbind writes its messages directly to
the system console, /dev/console.
Information logged to the file includes the date and time of the message, the host
name, the process id and name of the function generating the message, and the
message itself. Note that different services can share a single log file since enough
information is included to uniquely identify each message.
ypbind recognizes the following options:
-l log_file Log diagnostic and error messages to the file, log_file. See the description above.
-s Secure. When specified, only NIS servers bound to a reserved port are used. This
allows for a slight increase in security in completely controlled environments, where
there are no computers operated by untrusted individuals. It offers no real increase
in security.
-ypset Allow ypset to be used to change the binding (see ypset (1M)). For maximum secu-
rity, this option should be used only when debugging the network from a remote
machine.
-ypsetme Allow ypset to be issued from this machine (see ypset (1M)). Security is based on
IP address checking, which can be defeated on networks where untrusted individu-
als may inject packets. This option is not recommended.
-broadcast When ypbind is invoked with this option, ypbind will try to establish a binding
by broadcast even though the file
/var/yp/binding/domain_name /ypservers exists. That is, the option
-broadcast overrides the existence of this file.
If
-broadcast is used in conjunction with -ypset or -ypsetme, then the
-broadcast option is ignored. If ypbind is invoked with option -ypset or
-ypsetme the NIS servers list in the file
/var/yp/binding/domain_name /ypservers is ignored.
Section 1M−−958 Hewlett-Packard Company − 2 − HP-UX 11i Version 2: September 2004