Summary with further Question: Domain Name System protection

Tue Aug 17 13:46:11 UTC 2004

> What I'm not sure about ACL on router is, how to
> survive DNS server under DoS/DDos attack. We suffered
> from DoS attack last year, and we found the source IPs
> of that attack locate in our customers IP address
> blocks. ACL on router could only filter those traffic
> not meaningful to DNS server, but how about those DDoS
> attacking packets?

Your router can presumably rate limit the traffic towards the name
server to a level the name server can handle. On the name server
you can perform further rate limiting on an IP address basis, with
for instance FreeBSD ipfw.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no