Use of DNS servers

[Forrest Aldrich]

We noticed recently that one of our PoP DNS servers was getting an 
unusually high load of traffic.

Upon further investigation, we discovered that other people (even 
competitors) were utilizing our DNS servers to perform regular 
queries.   Some of these people were never customers of ours, and simply 
wouldn't have known about the DNS server being there, unless through some 
other means.

We do deny draft-manning-dsua-03 updates on some of our servers; this one 
we weren't for some reason.

So, before we draw conclusions about this usage, I'm wondering if someone 
can shed some light on how this might occur, and perhaps what other people 
have done about it.

At this point, we dropped in ACLs in named.conf.  We will next drop in some 
packet filters.


Thanks.