On 2012.02.05 22:30, Keegan Holley wrote:
2012/2/5 Steve Bertrand <steve.bertrand@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 ;) Steve