I'm using dynamic DNS (the "adult" version from RFC 2136, not à la DynDNS), and for a while now I've been seeing my laptops with MacOS 10.6.x churning out updates about every 10 seconds. And seemingly redundant updates at that, as the IP is more or less stable (consumer broadband). I don't remember seeing that frequency in the (distant...) past.
The lowest time-to-live that MacOS pushes on the entries is 2 minutes, so I have no clue what's going on.
...
Jan 12 13:17:18 lambda named[18683]: info: client 84.208.X.X#48715: updating zone 'dynamic.foldr.org/IN': deleting rrset at 'rCosinus._afpovertcp._tcp.dynamic.foldr.org' SRV
Jan 12 13:17:18 lambda named[18683]: info: client 84.208.X.X#48715: updating zone 'dynamic.foldr.org/IN': adding an RR at 'rCosinus._afpovertcp._tcp.dynamic.foldr.org' SRV
Jan 12 13:17:26 lambda named[18683]: info: client 84.208.X.X#48715: updating zone 'dynamic.foldr.org/IN': deleting rrset at 'rcosinus.dynamic.foldr.org' AAAA
...
Additionally, I can't find out what triggers the updates on the laptop-side. Is this a known problem, and how would I go about debugging it? One of the machines is freshly purchased and installed. The only "major" change was installation of the Miredo client for IPv6/Teredo, but even disabling it didn't make a change (except that AAAA records are no longer published).
(Crossposted to the Apple exchange).
This is due to your Apple equipment using Dynamic DNS to announce zeroconf features (also known as Bonjour), it's pretty common that these features get registered and deregistered (I'm experiencing the same at home using dynamic DNS).
You can also reduce debugging on the DNS config if you wish to avoid huge log files :)
Hm, must have been something transient: I noticed that the SOA didn't change, and after a zone freeze/thaw, the problem suddenly disappeared. Looks like BIND might have had a hick-up.