Q. Why is the secondary nameservers not picking up the change to a DNS zone file on the primary nameserver?

A. When making a change to a DNS zone file, the Serial # field MUST be incremented in order for the secondary nameservers to realize that a change has been made and to request a zone transfer. The Serial number is located in the SOA record that is generally at the top of a zone file. The following is an example of an SOA record:

@ IN SOA host.domain. sysmgr. host.domain. (

25; Serial

3600; Refresh

600; Retry

3600000; Expire

86400); Minimum

In this case the serial number of 25 would be incremented to 26 if you were to make a change to this file.