5.7. DoS Defense Strategy
With some exceptions (such as with vulnerabilities that can be easily
fixed) DoS attacks are very difficult to defend against. The main
problem remains being able to distinguish legitimate requests from
requests belonging to an attack.
The chapter concludes with a strategy for handling DoS attacks:
Treat DoS attacks as one of many possible risks. Your assessment
about the risk will influence the way you prepare your defense.
Learn about the content hosted on the server. It may be possible to
improve software characteristics (and make it less susceptible to DoS
attacks) in advance.
Determine what you will do when various types of attacks occur. For
example, have the contact details of your upstream provider ready.
Monitor server operation to detect attacks as soon as possible.
Act promptly when attacked.
If attacks increase, install automated tools for defense.