Re: Is there a line of defense against Distributed Reflective attacks?

["Christopher L. Morrow" <chris () UU NET>]

On Fri, 17 Jan 2003, David G. Andersen wrote:

> On Fri, Jan 17, 2003 at 06:38:08PM +0000, Christopher L. Morrow mooed:
> > > has something called Source Path Isolation Engine (SPIE).  There
> >
> > This would be cool to see a design/whitepaper for.. Kelly?
>
> The long version of the SPIE paper is at:
>
>   http://nms.lcs.mit.edu/~snoeren/papers/spie-ton.html
>
> The two second summary that I'll probably botch:  SPIE keeps a (very tiny)
> hash of each packet that the router sees.  If you get an attack packet,
> you can hand it to the router and ask "From where did this come?"
> And then do so to the next router, and so on.  The beauty of the scheme
> is that you can use it to trace single-packet DoS or security attacks
> as well as flooding attacks.  The downside is that it's hardware.

This sounds like Steve Bellovin's thing called 'icmp traceback' where you
make up a new icmp type message and send that query through the system,
hop by hop... though I say that after only reading your blurb, not the
paper :)

As I recall the icmp thing (that might NOT have been all steve, I just
heard him present it once) was a problem from a memory and processing
perspective, not to mention 'no router does this today' so its a 3 year
off feature addition... nevermind the protocol additions :)