Red Hat has just moved coverage of Network Time Protocol services to the RHCSA objectives, listed at http://www.redhat.com/certification/rhcsa/objectives/ The NTP objective is now listed in under the following RHCSA category: Deploy, Configure, and Maintain Systems, and reads as follows:

Previously, the configuration of NTP servers, as peers, was part of the RHCE requirements.

The current (6th) edition of my book includes coverage of an NTP client in Chapter 5. The configuration listed in that chapter actually works as an NTP server limited to the local system. The information required to set up NTP as a server for a specific network is covered in Chapter 17.

To set up a default NTP server, you'll need to make a couple of changes to the default /etc/ntp.conf configuration file:

First, you'll need to set up a restrict directive to open up access to the local network. One already exists in the comments of the default version of the file, as shown here:

Obviously, you'll want to change the directive to the network whose clients use the NTP server. The default shown here works if there's a connection to the Internet:

But as you shouldn't expect access to the Internet, you should be prepared to change the rhel.pool.ntp.org URIs as defined for the local network.

A little additional work is required to set up an NTP server as a peer, as defined in Chapter 17. Bottom line, all you need to do is change server to peer in the /etc/ntp.conf file, and make sure the URIs of the NTP servers are accessible and accurate. (Hint: by default, NTP communicates over UDP port 123)