Bug ID 598204: In syncookie mode, TCP profile MSS is not honored when the BIG-IP system sends back the SYN-ACK.

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6

Fixed In:
13.0.0

Opened: Jun 09, 2016

Severity: 3-Major

Related Article: K54284420

Symptoms

In syncookie mode, TCP profile MSS is not honored when the BIG-IP system sends back the SYN-ACK.

Impact

A TCP virtual server might use bigger MSS in syncookie mode and not honor the MSS specified in the profile. Some configurations require a smaller MSS for certain virtual servers, rather than using the VLAN's MTU to calculate the MSS.

Conditions

This occurs when the following conditions are met: -- TCP profile. -- syncookie mode.

Workaround

None.

Fix Information

In syncookie mode, the system now honors the MSS value set in the TCP profile when the BIG-IP system sends back the SYN-ACK.

Behavior Change

In syncookie mode, the system now honors the MSS value set in the TCP profile when the BIG-IP system sends back the SYN-ACK.

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips