Re: TCP RST attack (the cause of all that MD5-o-rama)

[vijay gill <vgill () vijaygill com>]

On Tue, Apr 20, 2004 at 02:11:02PM -0700, Dan Hollis wrote:
> On Tue, 20 Apr 2004, Crist Clark wrote:
> > But it has limited effectiveness for multi-hop sessions. There is the
> > appeal of a solution that does not depend of the physical layout of the
> > BGP peers.
>
> Does MD5 open the door to cpu DOS attacks on routers though? Eg can 
> someone craft a DOS attack to take out the CPU on a router by forcing it 
> to MD5 authenticate torrents of junk packets, using less bandwidth than 
> it would take to DOS the links themselves?

Yes it does. About 5 mbit of md5 should peg a juniper at 100% according
to my friend alex.  I have not verified this in the lab.  I suggest
you try it out.

Also, this is why the GTSM (ttl hack) was written up ;)

/vijay