Short overview of the problem set and any back ground material or references one would need to understand the details. If the value of sn from the master DNS SOA is the same or LOWER then no zone transfer is initiated.
If the sn value from the master is arithmetically HIGHER than that currently stored by the slave then a zone transfer (AXFR/IXFR) is initiated.
named: client 18.104.22.168#33606: received notify for zone 'domain.tld' named: master 22.214.171.124#53 (source 0.0.0.0#0) deleted from unreachable cache named: zone domain.tld/IN: Transfer started.
In the hosting industry, the Domain Name System (DNS) is one of the most critical pieces, right behind websites themselves.
The default behaviour is enabled (yes), which means that it will try to forward.
In the processing of the update packet, the allow-dnsupdate-from and TSIG-ALLOW-DNSUPDATE are processed first, so those permissions apply before the forward-dnsupdate is used.
Quotations from Zytrax DNS book: sn = serial number This value MUST increment when any resource record in the zone file is updated.
Enhanced DNS is designed to integrate easily with your existing DNS infrastructure to provide a secure, high performance, highly available and scalable solution for DNS hosting.
As part of this service, Akamai runs name servers in multiple networks and in many geographic locations that are capable of resolving queries for your zones.
Maintaining single global SOA serial for all servers was found as hard problem.
Attributes like can't be used because they can go back in time (because of replication).It was reproduced 100% of the time, and required a complete restart in order to get the touchpad working again.