[105172] in North American Network Operators' Group
Re: DNS problems to RoadRunner - tcp vs udp
daemon@ATHENA.MIT.EDU (John Kristoff)
Fri Jun 13 15:06:12 2008
Date: Fri, 13 Jun 2008 14:05:44 -0500
From: John Kristoff <jtk@ultradns.net>
To: nanog@merit.edu
In-Reply-To: <4852B91F.8090205@aset.com>
Errors-To: nanog-bounces@nanog.org
On Fri, 13 Jun 2008 14:14:55 -0400
Jon Kibler <Jon.Kibler@aset.com> wrote:
> TCP is used for zone transfers.
> If my server responded to TCP queries from anyone other than a secondary
> server, I would be VERY concerned.
I wouldn't be unless it looked like a DDoS - and it might for some that
are seeing the results of a DNS-based DDoS mitigation device you or an
upstream put in for the first time. These boxes force clients to switch
over from UDP to TCP for queries when a well formed UDP DNS attack hits.
John
