Massive increase of SERVFAIL after April 28th 2025.

[Mark Andrews]

I don’t think there was anything wrong with your servers.  The log messages
indicate problems with the authoritative servers.

In theory authoritative DNS servers should be able to serve content until the
zone content expires.  They should be able to be powered off then rebooted and
continue to serve the content they had provided it hasn’t expired in the meantime
by reading it off local disc drives.  This obviously has not happened for the
zones you mentioned.  The servers appear to have come up without access to the
zone content they are supposed to serve and are hence returning SERVFAIL.

Forwarding to the servers you are is providing indirect access to instances with
zone content to serve.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka at isc.org