Re: DNS requests from 209.67.50.203 (fwd)

[Joe Shaw <[EMAIL PROTECTED]>]

The following came across the NANOG list today.  Anyone else experiencing
this?  I have not seen mention of this specific attack previously, but
realize that I may have overlooked it.

Regards,
--
Joseph W. Shaw
Sr. Network Security Specialist for Big Company not to be named.
I have public opinions, and they have public relations.

---------- Forwarded message ----------
Date: Tue, 09 Jan 2001 19:24:39 -0500
From: Steven M. Bellovin <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]
Subject: Re: DNS requests from 209.67.50.203


In message <[EMAIL PROTECTED]>, John Kristoff writes:
>
>I'm surprised this hasn't come up in NANOG yet...
>
>On a university list many sites are reporting large amounts of traffic
>appearing to come from 209.67.50.203 to their DNS servers.  The
>administrator of the source IP (spoofed of course) is the victim of a
>brutal DoS attack.  The traffic is UDP/DNS queries that are appear to be
>going directly to available DNS servers (as opposed to random hosts).
>Most sites are reporting on the order of 6 or more packets per second to
>their DNS servers.  The victim has apparently seen upwards of 90 Mb/s of
>traffic coming back in to them.  Does anyone here have anymore
>information on this attack?

Yes, it's a DDoS attack, of the type that Vern Paxson has dubbed
"refletor attacks".  You send a forged DNS query to a DNS server; it
sends its reply to the victim.  Then you have lots of hosts around the
net doing this, but banging on different DNS servers.



		--Steve Bellovin