2009-09-28 - News - Chris Thompson
Last Saturday (26 September) we started to change SOA serial numbers
for the zones managed by the Computing Service from "seconds since 1900"
to "seconds since 1970" (the latter being familiar as the POSIX time_t
value). We had made sure that this was an increase in RFC 1982
(published August 1996) terms. No version of BIND has any problem with this.
Unfortunately, we did not foresee that many versions of Windows DNS Server (apparently even those as late as Windows 2003 R2) cannot cope with this change, repeatedly attempting to transfer the zone at short intervals and discarding the result. We are seeing a great deal of churning on our authoritative nameservers as a result. (This affects servers that are fetching from 131.111.12.73 [fakedns.csx.cam.ac.uk] as well.)
It is too late for us to undo this change. If you are running Windows DNS Server and are failing to fetch cam.ac.uk and similar DNS zones, you should discard your existing copy of the zone(s). Andy Judd advises us that you "need to delete the zone in a DNS MMC and then delete the zone files from C:\Windows\System32\dns and C:\Windows\System32\dns\backup, then re-create the zone". Please ask Hostmaster and/or PC Support for assistance if necessary.
We shall be contacting the administrators of the hosts that are causing the most continuous zone-fetching activity on our servers.