nanog mailing list archives

Re: Effective ways to deal with DDoS attacks?


From: Richard A Steenbergen <ras () e-gerbil net>
Date: Thu, 2 May 2002 13:19:03 -0400


On Thu, May 02, 2002 at 08:07:31PM +0200, Hank Nussbacher wrote:

At 12:23 PM 02-05-02 -0400, Richard A Steenbergen wrote:

Thats what the IP2 does, match bytes in the headers and come back with a
thumbs down or a thumbs up and a destination interface. It's really not
that much harder to match the bytes for a dest port against a compiled
ruleset and decide yes or no then it is to match the dest address against
a forwarding table and decide which nexthop.

Looking into the IP header is not enough.  In order to filter DDOS packets 
one has to look into the payload as well.  I don't think routers are 
suitable for that level of filtering (think advanced NBAR).

I disagree. There are a world of things you can do when you look at the 
entire payload, from IDS to playing Big Brother. But stopping DDoS does 
not require it, in almost every case layer 3+4 headers is sufficient.

-- 
Richard A Steenbergen <ras () e-gerbil net>       http://www.e-gerbil.net/ras
PGP Key ID: 0x138EA177  (67 29 D7 BC E8 18 3E DA  B2 46 B3 D8 14 36 FE B6)


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