find the PID doing DNS queries?

[Dan Kressin]

We've got several RHEL boxes doing DNS queries against our old servers, even though resolv.conf has been updated (long ago) to point at our new servers.

Is there any way to determine the PID of the process(es) that are doing the DNS queries?  nscd is not running, so it's not that.

'netstat -npcuve' doesn't catch them, and tcpdump doesn't include the PID.

Ideas?

Thanks,
-Dan