Bug ID 613673: Pool members may not be marked up and/or there might be a slight delay in monitors

Last Modified: Jul 12, 2023

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

Known Affected Versions:
12.0.0, 12.0.0, 11.6.1

Fixed In:
11.6.1 HF2

Opened: Aug 31, 2016

Severity: 3-Major

Related Article: K48693281


A UDP monitor might fail to mark a pool member up even when the pool member is up. Other monitor types may mark a pool member down. A slight delay (less than 0.1 seconds) might be noticed in monitor traffic sent by the BIG-IP.


Incorrect pool member status or pool member flapping. Connections to monitored pool members might last slightly longer than necessary.


To experience the incorrect pool member status issue, there is generally some other monitor on the system that is legitimately down. To experience the delay, run an affected version. The issue has been observed with TCP, HTTP, and HTTPS monitors.



Fix Information

In this release, the system now correctly sets pool member status and connections to monitored pool members no longer last longer than necessary.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips