Dns zone serial number

Note Each DNS record in the zone has a copy of the zone serial number at the time when the record was last modified. If the serial number of the replicated record is the same or lower than the local serial number, and if the local DNS server is configured not to allow zone transfer of the zone, the local zone serial number is not changed.

If the serial number of the replicated record is the same or lower than the local zone serial number, if the DNS server is configured to allow a zone transfer of the zone, and if the local zone serial number has not been changed since the last zone transfer occurred to a remote DNS server, then the local zone serial number will be incremented.

Otherwise that is if a copy of the zone with the current local zone serial number has not been transferred to a remote DNS server, the local zone serial number is not changed. In a scenario where a third-party DNS server is configured as secondary for an Active Directory-integrated zone, the first preferred master server becomes unavailable, and the secondary server attempts a zone transfer from another primary server for the zone, then the secondary DNS server by using IXFR may not notice that the zone was updated if the serial number of the zone is lower on the latter primary server.

In this scenario, the secondary successfully performs zone transfer after the primary's serial number becomes greater than the serial number in the SOA record in the zone on the secondary server. It is not possible to retrieve information pull or source from multiple Active Directory-integrated primary DNS servers to a secondary DNS server for the same Active Directory-integrated zone. This was possible and frequently done with conventional single-master DNS.

However, because serial numbers are maintained separately on each Active Directory-integrated DNS server, the mechanism for determining whether the secondary DNS server has the most-recent copy may will fail. Windows Servers More Need more help? While technically the serial number should be updated, I find many people do not actually have multiple nameservers. Instead, all nameservers run from the same server. In this case, the serial number does not matter since the primary and secondary server are one in the same.

If you don't have multiple content DNS servers, you aren't replicating your database anywhere. And if you are not using the "zone transfer" database replication mechanism, you very probably aren't using a mechanism that relies on anything in that entire resource record set in the first place.

I suspect that you are using "zone transfer" and have multiple content DNS servers. But that's just an educated guess on my part, since you don't say in your question. If so, remember that a change can comprise multiple resource records in one go. Serial number updates are tied to changes, not to single resource records. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Learn more. DNS records serial number Ask Question. Asked 10 years ago. Active 9 years, 11 months ago. Viewed 6k times. Thanks Jean.

Improve this question. Customer cases. Live demo. Support center. Developers API. What's new. View all tools. Some info may not yet be up to date. Please check From classic to new UI. First, you need to get the current serial number To get the current serial number, you need to perform an SOA query.