How To Stop a DDOS Attack

How to stop a DDOS attack? How to block DDOS attacks? Or: How to stop getting DDOSed?

The first answer to these common questions is: Get a plan!

Remarkably, many companies have no DDOS protection plan.

"Nearly 45 percent of organizations surveyed by Corero have no DDoS response plan, while some 21 percent don't have a response team set up in the case of a DDoS attack targeting their networks. Around 60 percent say they don't have a designated DDoS response team, and 40 percent say they don't have a point of contact within their organizations when a DDoS hits, according to the survey of some 100 respondents:" Dark Reading report on recent study, Nov. 2013.
http://www.darkreading.com/attacks-breaches/survey-ddos-is-hot-planning-is-not/240164306

The study also found that most respondents don't have statistics on normal network traffic patterns, making it even harder to detect and stop a DDOS attack.