Bug ID 584717: TCP window scaling is not applied when SYN cookies are active

Last Modified: Apr 10, 2019

Bug Tracker

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

Known Affected Versions:
11.5.0, 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

Fixed In:
11.5.4 HF2

Opened: Mar 31, 2016
Severity: 3-Major

Symptoms

TCP window scaling is not applied, which can be observed in transmitted packets containing small segments that are about the size of the unscaled window.

Impact

Poor performance / throughput.

Conditions

SYN cookies have been activated.

Workaround

None

Fix Information

The tmm now properly scales the TCP window upon SYN cookie activation.

Behavior Change