UDP port 80 DDoS attack

Steve Bertrand steve.bertrand at gmail.com
Mon Feb 6 03:40:19 UTC 2012

On 2012.02.05 22:30, Keegan Holley wrote:
  > 2012/2/5 Steve Bertrand <steve.bertrand at gmail.com
>     On 2012.02.05 20 <tel:2012.02.05%2020>:37, Keegan Holley wrote:
>         Source RTBH often falls victim to rapidly changing or spoofed
>         source IP"s.
>         It also isn't as widely supported as it should be. I never said
>         DDOS was
>         hopeless, there just aren't a wealth of defenses against it.
>     This is so very easily automated. Even if you don't actually want to
>     trigger the routes automatically, finding the sources you want to
>     blackhole is as simple as a monitor port, tcpdump and some basic Perl.
> This is still vulnerable to spoofing which could cause you to filter
> legitimate traffic and make the problem worse.  Not saying that S/RTBH
> is a bad idea.  RTBH is effective and a great idea just not very elegant.

Agreed. Diligence does play a role. However, the times I have 
implemented and used (s/)RTBH, I thought it was most elegant. I love its 
simplicity and effectiveness.

>     ...and as far as this not having been deployed in many ISPs (per
>     your next message)... their mitigation strategies should be asked up
>     front, and if they don't have any (or don't know what you speak of),
>     find a new ISP.
> You sometimes have to weigh the pro's and cons.  You can't always pick
> the guys with the coolest knobs.

Agreed. But to me, DDOS mitigation is not just a cool knob. If my ISP 
can help mitigate a 1Gb onslaught so my 100Mb pipe isn't overwhelmed, 
that's more functional than cool. Ranks right up there with IPv6 ;)


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