stops answering at same time every day

[Allie M Hopkins]

All three of our nameservers - two running 9.3.0 and one running 9.2.3 -
stop answering at the same time every afternoon.  Not all three everyday -
sometimes just one, sometimes two, sometimes all three, but always at
6:30pm for 10-15 minutes.  My first thought was that a script or other os
application was stopping the service from answering but I've been running
logs and nothing points to anything peculiar.  No crontabs, no extra
processes running.


I'm going to turn on query logging during this interval to see what the
clients are doing, perhaps something is hosing the servers making it unable
to respond.  I know about the cleaning interval, but I thought the default
was 60 minutes.  I don't have this option set anywhere to change the
default.  I just can't seem to figure it out.  No weird connections at this
time either, according to netstat.

Anyone have any ideas???  I'm running AIX 4.3.3.  What other logs can I
turn on to get a better handle on the situation?

MRTG is graphing the traffic load.  You can see the dips on the servers:
http://kahuna.net.lsu.edu/mrtg/dns.html

Allie M Hopkins