Network Information Service (NIS)
The NIS (Network Information Service) also known as YP (Yellow Pages) is a client-server directory service protocol for distributing system configuration. NIS/YP is used for keeping a central directory of user names and passwords, hostnames and their IP addresses, and most other useful things in a computer network.
Configuring a NIS/YP client
In order to setup a machine to be a NIS/YP client, your system must have the following programs:
- ypbind
- ypcat/ypset
- portmap
RPM based systems can easily get these programs by installing the portmap, ypbind, and yp-tools packages. Next, make sure that your /etc/nsswitch.conf is set to
:passwd: files nis nisplus :shadow: files nis nisplus :group: files nis nisplus
This allows the system to first try the local files (i.e. /etc/hosts, /etc/passwd) before using the the NIS (or the NIS+) service. This means that if a particular user has a local account on machine A, then this user can log into machine A, but not machine B or C. However, if this user has an entry on the NIS server, then machines B and C will allow this user to login as well. Conversely, if a different user tries to log into machine A and that user also has an entry on the NIS server, then that user will be able to login also.
Next, modify the /etc/yp.conf file to specify the domain and the NIS server name:
:domain my.domain.com server MyNISServer
and the /etc/hosts file to define the IP address of the NIS server:
:10.1.2.3 MyNISServer
Lastly, edit your /etc/rc.d/rc.sysinit to add:
:NISDOMAIN=my.domain.com
Make sure that your portmap and ypbind services startup at boot time, and reboot your system. Now, you should be able to type commands like:
:$ypcat hosts :$ypcat passwd
to see all NIS defined hostnames and users.