Datasheet
“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 505 — #531
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21
Linux in the Network
21.9 NIS — Network Information
Service
As soon as multiple UNIX systems in a network want to access common
resources, it becomes important that all user and group identities are the
same for all machines in that network. The network should be transpar-
ent to the user: whatever machine a user uses, he always finds himself in
exactly the same environment. This is made possible by means of NIS and
NFS services. NFS distributes file systems over a network and is discussed
in Section 21.10 on page 510.
NIS (Network Information Service) can be described as a database-like ser-
vice that provides access to the contents of /etc/passwd, /etc/shadow,
and /etc/group across networks. NIS can also be used for other pur-
poses (to make available the contents of files like /etc/hosts or /etc/
services, for instance), but this is beyond the scope of this introduction.
People often refer to NIS as YP, which simply stands for the idea of the net-
work’s “yellow pages.”
21.9.1 NIS Master and Slave Servers
For the configuration, select ‘NIS Server’ from the YaST module ‘Network
Services’. If no NIS server existed so far in your network, activate ‘Install
and Set up a Master NIS Server’ in the next screen. If you already have a
NIS server (a master), you can add a NIS slave server (for example, if you
want to configure a new subnetwork). First, the configuration of the master
server is described.
If some needed packages are missing, insert the respective CD or DVD as
requested to install the packages automatically. Enter the domain name at
the top of the configuration dialog, which is shown in Figure 21.32 on the
next page. With the check box, define whether the host should also be a NIS
client, enabling users to log in and access data from the NIS server.
To configure additional NIS servers (slave servers) in your network after-
wards, activate ‘Active Slave NIS Server Exists’ now. Select ‘Fast Map Dis-
tribution’ to set fast transfer of the database entries from the master to the
slave server.
505SUSE LINUX Enterprise Server