Abstract
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 transparent to users: whatever machines they use, they always find themselves 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 Chapter 39, Sharing File Systems with NFS.
NIS (Network Information Service) can be described as a database-like
service that provides access to the contents of
/etc/passwd
, /etc/shadow
, and
/etc/group
across networks. NIS can also be used for
other purposes (making the contents of files like
/etc/hosts
or /etc/services
available, for example), but this is beyond the scope of this
introduction. People often refer to NIS as YP,
because it works like the network's “yellow pages.”
To distribute NIS information across networks, you can either have one single server (a master) that serves all clients or you can have NIS slave servers requesting this information from the master and relaying it to their respective clients.
To configure just one NIS server for your network, proceed with Section 36.1.1, “Configuring a NIS Master Server”.
If your NIS master server should export its data to slave servers, set up the master server as described in Section 36.1.1, “Configuring a NIS Master Server” and set up slave servers in the subnets as described in Section 36.1.2, “Configuring a NIS Slave Server”.
To configure a NIS master server for your network, proceed as follows:
Start
+ + .If you need just one NIS server in your network or if this server is to act as the master for further NIS slave servers, select
. YaST installs the required packages.![]() | Tip |
---|---|
If NIS server software is already installed on your machine, initiate the creation of a NIS master server by clicking . |
Determine basic NIS setup options:
Enter the NIS domain name.
Define whether the host should also be a NIS client, enabling users to log in and access data from the NIS server, by selecting
.Select yppasswd).
to allow users in your network (both local users and those managed through the NIS server) to change their passwords on the NIS server (with the command
This makes the options
GECOS” means
that the users can also change their names and address settings with
the command ypchfn. “SHELL” allows
users to change their default shell with the command
ypchsh, for example, to switch from bash to sh.
The new shell must be one of the predefined entries in
/etc/shells
.
If your NIS server should act as a master server to NIS slave servers in other subnets, select
.Select
to have YaST adapt the firewall settings for the NIS server.
Leave this dialog with /etc
by default). In
addition, passwords can be merged here. The setting should
be so the files
(/etc/passwd
, /etc/shadow
,
and /etc/group
) are used to build the
user database. Also
determine the smallest user and group ID that should be
offered by NIS. Click
to confirm your settings and return to the previous screen.
If you previously enabled
, enter the hostnames used as slaves and click .If you do not use slave servers, the slave configuration is skipped and you continue directly to the dialog for the database configuration. Here, specify the maps, the partial databases to transfer from the NIS server to the client. The default settings are usually adequate. Leave this dialog with .
Check which maps should be available and click
to continue.Enter the hosts that are allowed to query the NIS server. You can add, edit, or delete hosts by clicking the appropriate button. Specify from which networks requests can be sent to the NIS server. Normally, this is your internal network. In this case, there should be the following two entries:
255.0.0.0 127.0.0.0 0.0.0.0 0.0.0.0
The first entry enables connections from your own host, which is the NIS server. The second one allows all hosts to send requests to the server.
Click
to save changes and exit the setup.To configure additional NIS slave servers in your network, proceed as follows:
Start
+ + .Select
and click .![]() | Tip |
---|---|
If NIS server software is already installed on your machine, initiate the creation of a NIS slave server by clicking . |
Complete the basic setup of your NIS slave server:
Enter the NIS domain.
Enter hostname or IP address of the master server.
Set
if you want to enable user logins on this server.Adapt the firewall settings with
.Click
.Enter the hosts that are allowed to query the NIS server. You can add, edit, or delete hosts by clicking the appropriate button. Specify from which networks requests can be sent to the NIS server. Normally, this is all hosts. In this case, there should be the following two entries:
255.0.0.0 127.0.0.0 0.0.0.0 0.0.0.0
The first entry enables connections from your own host, which is the NIS server. The second one allows all hosts with access to the same network to send requests to the server.
Click
to save changes and exit the setup.