Symptoms

Lower throughput at very high levels of SYN flood. A more obvious symptom is an "Attack Detected" log message.

Impact

CPS degrades 5-13%, depending on platform.

Conditions

This degradation occurs only under high rate of new TCP connection creation, typically when CPU usage is greater than 60%.

Workaround

Change device DoS detection threshold from default to infinite.

Fix Information

Change in default DoS attack detection threshold can degrade L4 performance

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips