Bug ID 467551: TCP syncookie and Selective NACK (profile option) causes traffic to be dropped

Last Modified: Feb 13, 2019

Bug Tracker

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

Known Affected Versions:
11.0.0, 11.1.0, 11.2.0, 11.2.1, 11.3.0, 11.4.0, 11.4.1, 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, 11.6.0, 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

Fixed In:
12.0.0, 11.6.3, 11.5.4

Opened: Jun 17, 2014
Severity: 3-Major
Related AskF5 Article:
K17011

Symptoms

TCP syncookie and Selective NACK (profile option) causes traffic to be dropped.

Impact

Traffic might be dropped.

Conditions

This occurs when the following conditions are met: -- Selective NACK enabled in TCP profile. -- TCP syncookie mode. -- No Selective NACK option in TCP options from client SYN.

Workaround

Disable Selective NACK option in TCP profile.

Fix Information

TCP syncookie and Selective NACK (profile option) now works correctly.

Behavior Change