[133320] in North American Network Operators' Group
Re: Over a decade of DDOS--any progress yet?
daemon@ATHENA.MIT.EDU (Michael Costello)
Wed Dec 8 11:59:46 2010
Date: Wed, 8 Dec 2010 11:58:46 -0500
From: Michael Costello <mc3401@columbia.edu>
To: nanog@nanog.org
In-Reply-To: <F3318834F1F89D46857972DD4B411D70019C4766CE@EXCHANGE.thenap.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Wed, 8 Dec 2010 11:13:01 -0500
Drew Weaver <drew.weaver@thenap.com> wrote:
> The most common attacks that I have seen over the last 12 months, and
> let's say I have seen a fair share have been easily detectable by the
> source network.
>
> It is either protocol 17 (UDP) dst port 80 or UDP Fragments (dst port
> 0..)
>
> What valid application actually uses UDP 80?
The Cisco NAC client for Macs, for the purpose of "VLAN change
detection", sends UDP/80 packets to the host's reversed default
gateway (i.e., if the actual gateway is 1.2.3.4, it sends the packets
to 4.3.2.1) once every five seconds.
mc
