Bug ID 513436: Setting source-port to preserve-strict in HW guaranteed mode

Last Modified: Nov 07, 2022

Bug Tracker

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

Known Affected Versions:
12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4

Opened: Mar 19, 2015
Severity: 2-Critical

Symptoms

Setting the virtual server option 'source-port' to 'preserve-strict' causes client-side and server-side flows to hash to different TMMs.

Impact

This results in server-side flows being fast forwarded, and in hardware acceleration guaranteed mode, the TMM fast forwarded flows will be reset causing a small percentage of client connections to be disconnected prematurely.

Conditions

This occurs when the following conditions are met: -- A virtual server is configured with a FastL4 profile using 'guaranteed' hardware acceleration (ePVA). -- The virtual server 'source-port' is set to 'preserve-strict'.

Workaround

Although this is intended functionality, setting virtual server 'source-port' to 'preserve' or less allows the TMM to source from a port hashing to the same TMM as the client-side.

Fix Information

None

Behavior Change