Bug ID 447515: CMP reply occasionally matches wrong connflow

Last Modified: Oct 16, 2023

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

Known Affected Versions:
11.6.2 HF1, 11.4.1

Fixed In:
11.6.0, 11.5.1 HF6, 11.4.1 HF4

Opened: Feb 06, 2014

Severity: 3-Major

Related Article: K15579


The system might crash and the CMP reply occasionally matches wrong connflow.


CMP msg may match a wrong connflow, even with the revised connflow cookie. In addition, TMM memory might grow.


This intermittent issue occurs when TMM resumes a rule on a dead flow, which might occur at iRule resumption. This happens when an iRule is parked (e.g., for a table command), and then when the iRule is resumed, the related flow is already deleted from the conn table.


As a possible workaround to help avoid the issue, if you are using a UDP profile, check the idle_timeout value. If it is set to a low number, such as 2, try raising this value to a larger value such as 30.

Fix Information

Resolved intermittent issue that could cause an eventual crash when an iRule was parked longer than the time-out which caused the flow to be deleted but then the iRule is resumed and becomes in a bad state due to the missing flow.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips