New answers tagged audit
If you're looking for a professional service who can do this for you, take a look at RedWolf Security - http://www.redwolfsecurity.com/#!ddos_testing/cqd6 I've heard good things about their service, although I haven't used it, and I don't work for them.
In my experience I've come across the Low Orbit Ion Cannon. it is a common tool for ddos attacks. It is open source now I believe.
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