[MaraDNS list] MaraDNS and denial-of-service attacks
Sam Trenholme <[email protected]> Thu, 28 Mar 2013 08:51:55 -0700
| Newsgroups | gmane.network.dns.maradns.general |
|---|---|
| Message-ID | <CAJxgfkRbacgg0Yv94P4o5hDhAsMAp-KK-_m7KZZ3r+Lwa7nYKA@mail.gmail.com> |
I will probably make this entry a full blown blog, but in the meantime, in light of the huge (300Gb/S) distributed denial-of-service (DDOS) attack against Spamhaus that used DNS, here are my thoughts: * MaraDNS 1 and Deadwood do not support a technology called =93EDNS=94 that allows for large DNS packets. By only supporting 512-byte packets, both DNS servers do not allow for the 100x amplification used in this DDOS that other DNS servers have. * My DNS software does not come with unrestricted recursive access enabled by default, and the documentation strongly discourages open recursion. * I will have to double check, but, as I recall, the documentation and example configuration files do not include an example with unrestricted recursive access. One feature that would be nice would be to be able to restrict how much data my DNS server sends to a given IP (again, as noted above, MaraDNS/Deadwood already has a form of this because they do not support EDNS). Unfortunately, since I am not developing new features for MaraDNS like this without being compensated for my time, I would need a corporate or government grant to implement this. - Sam