Commands Reference, Volume 6

ypbind Daemon

Purpose

Enables client processes to bind, or connect, to an NIS server.

Syntax

/usr/lib/netsvc/yp/ypbind [ -s -ypset -ypsetme ]

Description

The ypbind daemon binds, or connects, processes on a Network Information Services (NIS) client to services on an NIS server. This daemon, which runs on every NIS client, is started and stopped by the following System Resource Controller (SRC) commands:

startsrc -s ypbind

stopsrc -s ypbind

When a client requests information from a Network Information Services (NIS) map, the ypbind daemon broadcasts on the network for a server. When the server responds, it gives the daemon the Internet address and port number of a host. This is the host that provides the information the client is seeking. The ypbind daemon stores this address information in the /var/yp/binding directory using a file name of domainname.version. Then, the next time the client wants to access an NIS map, the client's ypbind daemon refers to the addresses in the domainname.version file.

The ypbind daemon can maintain bindings to several domains and their servers -ypsetme simultaneously. The default domain is the one specified by the domainname command at startup time.

Notes:

If a domain becomes unbound (usually when the server crashes or is overloaded), the ypbind daemon broadcasts again to find another server.
To force a client to bind to a specific server, use the ypset command.
To find out which server a client is bound to, use the ypwhich command.
If the /var/yp/binding/domainname/ypservers file exists, ypbind will attempt to contact the servers listed in that file before broadcasting. The file should contain a list of server IP addresses, one per line.

Flags

-s	Runs the ypbind daemon in a secure mode on privileged communications ports.
-ypset	Indicates the local host accepts ypset commands from local or remote hosts.
-ypsetme	Indicates that the local host accepts ypset commands only from the local host. This flag overrides the -ypset flag if both are specified.

Notes:

If neither the -ypset or -ypsetme flags are specified, the local host rejects all ypset commands from all hosts. This is the most secure mode because the NIS server cannot change.
If neither the -ypset or -ypsetme flags are specified, the local host rejects all ypset commands from all hosts. This is the most secure mode because the NIS server cannot change. However, if no NIS servers exist on the networks directly connected to the client machine, then the -ypsetme flag must be used and the NIS server should be specified with the ypset command.

Files

/var/yp/binding directory	Contains Internet addresses and port numbers for NIS servers.
/var/yp/binding/domainname/ypservers	Contains a list of internet addresses, one per line, of servers to attempt to contact before broadcasting.
domainname.version	Binary file that contains the address and port number of the current NIS server.

Related Information

The domainname command, makedbm command, mkclient command, mkmaster command, mkslave command, ypcat command, ypinit command, ypmatch command, yppoll command,yppush command, ypset command, ypwhich command, ypxfr command.

System Resource Controller Overview in AIX 5L Version 5.2 System Management Concepts: Operating System and Devices.

Network File System (NFS) Overview for System Management in AIX 5L Version 5.2 System Management Guide: Communications and Networks.

Network Information Services (NIS) Overview for System Management in AIX 5L Version 5.2 Network Information Services (NIS and NIS+) Guide.

NIS Reference.