Bug ID 622856: BIG-IP may enter SYN cookie mode later than expected

Last Modified: Oct 01, 2018

Bug Tracker

Affected Product:  See more info
BIG-IP All(all modules)

Known Affected Versions:
11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.5.3 HF2, 11.5.4, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.5.5, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1, 11.6.1 HF1, 11.6.1 HF2, 11.6.2, 11.6.2 HF1, 11.6.3, 11.6.3.1, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2

Fixed In:
13.0.0, 12.1.2 HF1, 11.6.3.2, 11.5.6

Opened: Oct 14, 2016
Severity: 2-Critical

Symptoms

BIG-IP entry to SYN cookie mode may not occur even though traffic pattern would dictate that it should.

Impact

BIG-IP does not enter SYN cookie mode at the expected time.

Conditions

Verified accept enabled on a Virtual IP. Large volume of traffic being processed by BIG-IP.

Workaround

Disable verified accept on all VIP TCP profiles.

Fix Information

BIG-IP correctly enters SYN cookie mode when traffic pattern dictates that it should.

Behavior Change