dynamic update to SOA records

Anand Buddhdev anandb at ripe.net
Tue May 1 15:10:43 UTC 2012

On 01/05/2012 16:36, Chris Thompson wrote:

> Our regular DNS changes (via [scripted] nsupdate) always add the SOA
> explicitly (it's going to change anyway, after all), setting the serial
> to the Unix time(2) value. BIND may have been incrementing the serial
> itself as a result of re-signing activity, but we assume it hasn't
> been doing so as often as once a second...

At our request, ISC added an option to BIND 9.9, which allows it to
automatically set the serial number to unix time, so that we don't have
to explicitly set the SOA record each time.

If multiple updates arrive within the same second, then BIND just adds
+1 to the existing serial number, so that for brief periods, the unix
time will be in the "future". However, as time advances, the serial
number will soon be in the past, allowing new updates to set the serial
back to current unix time.


Anand Buddhdev

More information about the bind-users mailing list