Bug ID 452579: Core error possible on FastL4 mirrored connections

Last Modified: Nov 07, 2022

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(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

Fixed In:
11.6.0, 11.5.1 HF5

Opened: Mar 17, 2014
Severity: 2-Critical


On certain FastL4 mirrored connections, it is possible for the active system to experience a core error on new connections.


Inability to pass traffic on FastL4 mirrored flows.


This regression was introduced in engineering hotfixes, including the fix for Bug 450202. (hf4.128.36)


Reconfigure the FastL4 VIP as an L2 or L7 vip.

Fix Information

Corrected calculation of server-side MSS.

Behavior Change