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Re: Tightened DNS security question re: DNS amplification attacks.
From: Mark Andrews <Mark_Andrews () isc org>
Date: Wed, 28 Jan 2009 14:06:07 +1100


In message <Pine.LNX.4.64.0901271739380.27614 () mail pirk com>, Steve Pirk writes
:
On Wed, 28 Jan 2009, jay () miscreant org wrote:

Quoting John Martinez <jmartinez () zero11 com>:

Are we still seeing DNS DDoS attack?

Yep. I'm seeing ~2 queries/sec targetting 64.57.246.146.

Also seeing requests from 76.9.16.171 every 1 minute 2 seconds.


I run a small personal nameserver and even I am seeing requests for that 
address 64.57.246.146 at ~1/sec.

How many people have upgraded to the latest version of Bind 9? Reason
I ask is that when I do my nightly port scan of my server, I no longer see 
named listening to udp on a random high order port (for replies I believe?). 
Almost the next day, I started hearing about/seeing these DNS attacks.

        Totally unrelated.  Named now creates multiple listening
        ports on demand.

        Mark
 
Previous nmap scan showed:
53/tcp    open          domain
53/udp    open|filtered domain
33591/udp open|filtered unknown

Now nmap shows:
53/tcp    open          domain
53/udp    open|filtered domain

The listen port (> 32767 I believe) is no longer there with BIND 9.4.3-P1.
The port was bound at startup time and did not change as long as named was 
still running.
--
Steve
Equal bytes for women.
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews () isc org


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