On Nov 30, 2011, at 3:12 PM, Drew Weaver wrote:
From: Rob.Vercouteren () kpn com [mailto:Rob.Vercouteren () kpn com]
Sent: Wednesday, November 30, 2011 3:05 PM
To: MatlockK () exempla org; richard.barnes () gmail com; andrew.wallace () rocketmail com
Cc: nanog () nanog org; leland () taranta discpro org
Subject: RE: Recent DNS attacks from China?
Yes it is, but the problem is that our servers are "attacking" the so called source address. All the answers are
going back to the "source". It is huge amplification attacks. (some sort of smurf if you want) The ip addresses are
spoofed (We did a capture and saw all different ttl's so coming from behind different hops) And yes we saw the ANY
queries for all the domains.
I still wonder how it is still possible that ip addresses can be spoofed nowadays
We're a smaller shop and started receiving these queries last night, roughly 1000 queries per minute or less. We're
seeing that the source (victim) addresses are changing every few minutes, the TTLs vary within a given source
address, and while most of the source/victim addresses have been Chinese we are seeing a few which are not, such as
220.127.116.11 (Google). The queries are coming in to ns1.traffiq.com (perhaps ns2 also, I haven't checked) and are
for traffiq.com/ANY which unfortunately gives a 492 byte response.
Transit providers can bill for the denial of service traffic and they claim it's too expensive to run URPF because
of the extra lookup.