How often zone transfers should occur is a function of how often names and IP address mappings change within your domain. Note that unnecessary zone transfer could cause unnecessary network and server loads.
A zone transfer is nothing more than a file copy procedure. The entire contents of the database are copied from the primary (or master) to the secondary each time the secondary is 'notified' by the primary (or master) that there has been a change in the zone data.
You configure primary and secondary zones with the information needed to initiate and request zone transfers by using the SOA Record and Notify tabs of the Zone Properties dialog box. You can change the default zone transfer timers by using the SOA Record tab. You can change the following values that affect zone transfer:
The following figure illustrates the SOA Record tab.
Figure 9.10 SOA Record tab
On the primary zone, use the Notify tab of the Zone Properties dialog box to identify the secondary or secondaries to notify for the zone transfer. The following figure illustrates the Notify tab.
Figure 9.11 Notify Tab