Bug ID 726239: interruption of traffic handling as sod daemon restarts TMM

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.6.0, 11.6.1, 11.6.2, 11.6.3,,, 12.1.0, 12.1.1, 12.1.2, 12.1.3,,,,,,,, 13.1.0,,,,,,,,, 13.1.1, 14.0.0,,

Fixed In:
14.1.0,,, 12.1.4,, 11.5.9

Opened: Jun 29, 2018

Severity: 2-Critical


When the receiving host in a TCP connection has set its send window to zero (stopping the flow of data), following certain unusual protocol sequences, the logic in the TMM that persists in probing the zero window may enter an endless loop.


Lack of stability on the device. Traffic disrupted while tmm restarts.


When the TCP implementation is probing a zero-window connection under control of a persist timer.



Fix Information

This fix handles a rare TMM crash when TCP persist timer is active.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips