Bug ID 612694: TCP::close with no pool member results in zombie flows

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.6.0, 11.6.1, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2

Fixed In:
13.0.0, 12.1.2 HF1, 11.6.2

Opened: Aug 25, 2016

Severity: 3-Major

Related Article: K70557109


'tmsh show sys conn all-properties' shows connections whose idle time exceeds the timeout.


Connection does not tear itself down.


There is no pool member, and a TCP::close iRule activates (typically after a TCP::respond).


Make TCP::close conditional on pool failure, and rely on the pool failure to RST the connection rather than perform a clean TCP close.

Fix Information

The system now properly handles TCP teardown when TCP::close has already torn down the rest of the stack.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips