Mitigating DDoS Attacks
Outline
DDoS Attacks
DDoS Attacks (cont.)
Steps of launching DDoS attacks
Victim Types
Victim Types (cont.)
Impact of the attack
Summary of DDoS attacks
Challenges for defense mechanisms
Principles for counter measures
Which way to go? Proactive VS Reactive
Proactive VS Reactive (cont.)
Network Layer Defense
Packet Marking (Trace back)
Packet Marking (Trace back)
Application Layer Defense
Crux Issues
Summary

Proactive VS Reactive (cont.)

Reactive solutions aims at mitigate DDoS attacks when the victim suffers those attacks, or some DDoS attacks are detected.
Need some detection mechanisms. Less overhead in the normal situation.
The problem is how to identify DDoS attacks, what are the proper responses for different kinds of attacks?
Use models of attacks to detect. We can also define abnormal behaviors for detection, But have to be careful with false positive.
Block identified zombies, or rate limiting /filtering.