Re: Massive stupidity (Was: Re: TCP vulnerability)

[Mike Tancsa <mike () sentex net>]

At 05:09 PM 20/04/2004, Richard A Steenbergen wrote:

> party to know which side won the collision handling. Therefore you need
> 262144 packets * 3976 ephemeral ports (assuming both sides are jnpr, again
> worst case) * 2 (to figure out who was the connecter and who was the
> accepter) = 2084569088 packets to exhaustively search all space on this
> one single Juniper to Juniper session. Now, lets just for the sake of
> argument say that the router is capable of actively processing 10,000
> packets/sec of rst (a fairly exagerated number) and still have this be
> considered a tcp attack instead of a straight DoS against the routing
> engine. This will still take 208456 seconds, or 57.9 hours.
<snip>
I dont understand why the large differences in claims

http://www.ietf.org/internet-drafts/draft-ietf-tcpm-tcpsecure-00.txt

says
   Modern operating
   systems normally default the RCV.WND to about 32,768 bytes. This
   means that a blind attacker need only guess 65,535 RST segments
   (2^^32/(RCV.WND*2)) in order to reset a connection. At DSL speeds
   this means that most connections (assuming the attacker can
   accurately guess both ports) can be reset in under 200 seconds
   (usually far less). With the rise of broadband availability and
   increasing available bandwidth, many Operating Systems have raised
   their default RCV.WND to as much as 64k, thus making these attacks
   even easier.


Also, with the various 'bots' at peoples disposal, why the assumption the 
attack would not be distributed.

        ---Mike