From: Jussi Hirvi listmember@greenspot.fi
On 17.8.2012 8.18, John R Pierce wrote:
meh, if its coming from lots of random hosts, then fail2ban style techniques won't work. I assume this is an authoritative name server? does it have recursive queries disabled so it can only return results for the domain(s) its authoritative for ?
Yes, it is authoritative. Recursive queries were open very widely. That may be why I started to get plenty of requests. But I think that 240 per second is not normal anymore, it must me malicious.
I believe my name server was used as a mediator only, and the real target (through recursive queries) was some other public nameserver.
This morning I restricted recursive queries to trusted networks only. The load dropped slowly to 20 % of what it was before.
Maybe it is this: http://arstechnica.com/business/2012/03/how-anonymous-plans-to-use-dns-as-a-...
JD