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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
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.
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By default, the following files are served by NIS:
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
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