Planning a DNS Strategy

Plan to install and operate a primary name server and at least one secondary name server. Secondary name servers provide load balancing and robustness to your DNS implementation.

When you configure your zone, the primary name server is considered authoritative for the zone, meaning that it contains the most up-to-date information about the zone and all the hosts within it.

A secondary name server receives its zone data from the primary name server. When it starts up and at periodic intervals, the secondary name server queries the primary name server to determine whether the information it contains has been changed. If the zone information in the secondary name server is older than the zone information in the primary name server, a zone transfer occurs and the secondary name server receives the zone information from the primary name server.

Planning Zones

If you are running a primary name server and providing DNS service for a zone, the size or geography of your network might require creating subzones within the zone.

Keep the zone data as a separate partition and replicate the partition to all places on your network where you have a name server for the zone. Doing so enables independent replication of the zone data and also provides a degree of fault tolerance in the case of server down time.

Novell DNS Server as a Primary Name Server

You must install the Novell DNS server as a primary name server to have authoritative control over your zone and to take advantage of Dynamic DNS (DDNS), the dynamic updating of DNS by DHCP.

When operating the Novell DNS server as a primary name server, you use the DNS/DHCP Management Utility to make configuration changes. When you operate a primary name server, the zone data can receive dynamic updates from DHCP servers. Non-Novell secondary name servers can transfer data in from the Novell primary name server.

Novell DNS Server as a Secondary Name Server (to a Non-Novell Master)

If you plan to operate secondary DNS servers using Novell DNS/DHCP Services software to a non-Novell master name server, one Novell secondary name server must be specified as the Dynamic DNS (DDNS) or zone in server. The DDNS server receives zone transfer information from the non-Novell master server and provides updates to eDirectory^TM. Other Novell secondary name servers can then access the information within eDirectory.

Reasons for operating a Novell secondary name server to a non-Novell master name server include:

• You are using a master DNS server and do not want to designate it as a primary name server because of the responsibility it entails.
• This approach is easy to implement in your existing DNS model.
• You want to install more secondary name servers to provide better load balancing.
• You want to gradually make the transition to operating a primary name server.