NSD 3: updates stop after one week

Tue Dec 26 10:44:49 UTC 2006

After one week of normal operations, our experimental instance of nsd
3.0.3 no longer process updates (whatever the master and the
nameserver serves hundreds of zones).

There are no errors logged and tcpdump sees normal communication with
the master (nsd is 192.93.0.4):

10:24:27.558813 IP 192.93.0.4.38104 > 193.176.144.2.domain:  25782 [1n] [1au] IXFR? nl. (191)
10:24:27.576046 IP 193.176.144.2.domain > 192.93.0.4.38104:  25782- 1/0/1 SOA[|domain]

Cold-restarting the name server solves the problem (proving that there
is no connectivity issues). But I'm looking for a better solution.

The log only shows the success:

[1167127347] nsd[10495]: info: Zone tf serial 2006122100 is updated to 2006122200.

Not the failures or attempts. Is there a way to make the log more
talkative? I do not see the NOTIFY reception. I do not see the IXFR
queries. I find no "verbosity" parameter in nsd.conf?