7. Setting Up the NIS Client

7.1. The ypbind daemon

After you have succesfully compiled the software you are now ready to install it. A suitable place for the ypbind daemon is the directory /usr/sbin. Some people may tell you that you don't need ypbind on a system with NYS. This is wrong. ypwhich and ypcat need it always.

You must do this as root of course. The other binaries (ypwhich, ypcat, yppasswd, yppoll, ypmatch) should go in a directory accessible by all users, normally /usr/bin.

Newer ypbind versions have a configuration file called /etc/yp.conf. You can hardcode a NIS server there - for more info see the manual page for ypbind(8). You also need this file for NYS. An example:

ypserver 10.10.0.1
ypserver 10.0.100.8
ypserver 10.3.1.1

If the system can resolve the hostnames without NIS, you may use the name, otherwise you have to use the IP address. ypbind 3.3 has a bug and will only use the last entry (ypserver 10.3.1.1 in the example). All other entries are ignored. ypbind-mt handle this correct and uses that one, which answerd at first.

It might be a good idea to test ypbind before incorporating it in the startup files. To test ypbind do the following:

• Make sure you have your YP-domain name set. If it is not set then issue the command:

  /bin/domainname nis.domain

  where nis.domain should be some string _NOT_ normally associated with the DNS-domain name of your machine! The reason for this is that it makes it a little harder for external crackers to retreive the password database from your NIS servers. If you don't know what the NIS domain name is on your network, ask your system/network administrator.

• Start up "/sbin/portmap" if it is not already running.

• Create the directory /var/yp if it does not exist.

• Start up /usr/sbin/ypbind

• Use the command rpcinfo -p localhost to check if ypbind was able to register its service with the portmapper. The output should look like:

  program vers proto port 100000 2 tcp 111 portmapper 100000 2 udp 111 portmapper 100007 2 udp 637 ypbind 100007 2 tcp 639 ypbind

  or

  program vers proto port 100000 2 tcp 111 portmapper 100000 2 udp 111 portmapper 100007 2 udp 758 ypbind 100007 1 udp 758 ypbind 100007 2 tcp 761 ypbind 100007 1 tcp 761 ypbind

  Depending on the ypbind version you are using.

• You may also run rpcinfo -u localhost ypbind. This command should produce something like:

  program 100007 version 2 ready and waiting

  or

  program 100007 version 1 ready and waiting program 100007 version 2 ready and waiting

  The output depends on the ypbind version you have installed. Important is only the "version 2" message.

At this point you should be able to use NIS client programs like ypcat, etc... For example, ypcat passwd.byname will give you the entire NIS password database.

IMPORTANT: If you skipped the test procedure then make sure you have set the domain name, and created the directory

    /var/yp

This directory MUST exist for ypbind to start up succesfully.

To check if the domainname is set correct, use the /bin/ypdomainname from yp-tools 2.2. It uses the yp_get_default_domain() function which is more restrict. It doesn't allow for example the "(none)" domainname, which is the default under Linux and makes a lot of problems.

If the test worked you may now want to change your startupd files so that ypbind will be started at boot time and your system will act as a NIS client. Make sure that the domainname will be set before you start ypbind.

Well, that's it. Reboot the machine and watch the boot messages to see if ypbind is actually started.