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RE: UDP port 80 DDoS attack
From: Sven Olaf Kamphuis <sven () cb3rob net>
Date: Thu, 9 Feb 2012 13:07:50 +0000 (UTC)

Stop paying transit providers for delivering spoofed packets to the edge of your network and they will very quickly develop 
methods of proving that the traffic isn't spoofed, or block it altogether. =)


yes, very smart idea... which makes it completely impossible to have multihomed networks or simply kick out tunnel originated traffic over default gateways ... so, no, thanks.

we usually do it the other way around, if providers block "spoofed" traffic, we tell them to put their serverfarms somewhere else as thats not very optimized for tunnel termination at their facilities :P

(yes leaseweb, that means you ;)

-----Original Message-----
From: George Bonser [mailto:gbonser () seven com]
Sent: Wednesday, February 08, 2012 1:27 PM
To: bas; nanog
Subject: RE: UDP port 80 DDoS attack

77% of all networks seem to think so.

And it would be the remaining 23% that really need to understand how difficult they are making life for the rest of the 

However the remaining networks allow spoofed traffic to egress their

When that traffic enters my network, I have no method whatsoever to
differentiate it from any other traffic.

I'm not really thinking about traffic coming from the Internet.  I'm thinking about its originating location.  Correct, 
once it gets into the Internet, you really have no way to tell.

I could ask my upstream where they see it coming from, which will be
quite hard if they do not have pretty fancy systems.

At that point the game is really hard, agreed.  And if it is distributed, it could be coming from any number of places 
or from every single one of their upstreams.

But if they receive it from a peer, I am as good as lost in trying to
find the culprit.

Agreed.  That's why it is important to stop it at the source.


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