Bug ID 1088597: TCP keepalive timer can be immediately re-scheduled in rare circumstances

Last Modified: Apr 11, 2024

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

Known Affected Versions:
13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,,,, 13.1.4,, 13.1.5,, 14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,,,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 15.1.9,, 17.1.0,,,

Fixed In:
17.1.1, 15.1.10

Opened: Mar 21, 2022

Severity: 3-Major


In rare circumstances, the TCP timer is rescheduled immediately due to the utilization of the interval encompassing also the idle_timeout.


High CPU utilization potentially leading to reduced performance.


Virtual Server with: - TCP Profile - SSL Profile with alert timeout configured Another way this can occur is by manually deleting connections, which effectively only sets the idle timeout to 0.


If the alert timeout is not re-enabled in the SSL Profile that should be sufficient.

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips