IBM eServer Certification Study Guide: Cluster 1600 Managed by PSSP

© Copyright IBM Corp. 2003. All rights reserved. 537

Appendix B. NIS

There are four basic daemons that NIS uses: ypserv, ypbind, yppasswd, and

ypupdated. NIS was initially called yellow pages; hence, the prefix yp is used for

the daemons. They work in the following way:

 All machines within the NIS domain run the ypbind daemon. This daemon

directs the machine’s request for a file to the NIS servers. On clients and

slave servers, the ypbind daemon points the machines to the master server.

On the master server, its ypbind points back to itself.

 ypserv runs on both the master and the slave servers. It is this daemon that

responds to the request for file information by the clients.

 yppasswd and ypupdated run only on the master server. The yppasswd

daemon makes it possible for users to change their login passwords

anywhere on the network. When NIS is configured, the /bin/passwd

command is linked to the /usr/bin/yppasswd command on the nodes. The

yppasswd command sends any password changes over the network to the

yppasswd daemon on the master server. The master server changes the

appropriate files and propagates this change to the slave servers using the

ypupdated daemon.

B

Note: NIS serves files in the form of maps. There is a map for each of the files

that it serves. Information from the file is stored in the map, and it is the map

that is used to respond to client requests.

538 IBM Eserver Certification Study Guide: Cluster 1600 Managed by PSSP

By default, the following files are served by NIS:

 /etc/ethers

 /etc/group

 /etc/hosts

 /etc/netgroup

 /etc/networks

 /etc/passwd

 /etc/protocols

 /etc/publickey

 /etc/rpc

 /etc/security/group

 /etc/security/passwd

 /etc/services

To configure NIS, there are four steps, all of which can be done through SMIT.

For all four steps, first run smit nfs and select Network Information Service

(NIS)

to access the NIS panels, then:

 Choose Change NIS Domain Name of this Host to define the NIS domain.

Figure B-1 on page 539 shows what this SMIT panel looks like. In this

example, SPDomain has been chosen as the NIS domain name.

Tip : By serving the /etc/hosts file, NIS has an added capability for handling

name resolution in a network. Refer to NIS and NFS publications by O’Reilly

and Associates for detailed information.

Appendix B. NIS 539

Figure B-1 SMIT panel for setting an NIS domain name

 On the machine that is to be the NIS master (for example, the control

workstation), select Configure/Modify NIS

→ Configure this Host as a NIS

Master Server. Figure B-2 on page 540 shows the SMIT panel. Fill in the

fields as required. Be sure to start the yppasswd and ypupdated daemons.

When the SMIT panel is executed, all four daemons (ypbind, ypserv,

yppasswd, and ypupdated) are started on the master server. This SMIT panel

also updates the NIS entries in the local /etc/rc.nfs files.

540 IBM Eserver Certification Study Guide: Cluster 1600 Managed by PSSP

Figure B-2 SMIT panel for configuring a master server

 On the machines set aside to be slave servers, go to the NIS SMIT panels

and select Configure this Host as a NIS Slave Server. Figure B-3 on

page 541 shows the SMIT panel for configuring a slave server. This step

starts the ypserv and ypbind daemons on the slave servers and updates the

NIS entries in the local /etc/rc.nfs files.

Appendix B. NIS 541

Figure B-3 SMIT panel for configuring a slave server

 On each node that is to be a NIS client, go into the NIS panels and select

Configure this Host as a NIS Client. This step starts the ypbind daemon

and updates the NIS entries in the local /etc/rc.nfs files.

Figure B-4 SMIT panel for configuring an NIS client