Bug ID 450087: Unacknowledged segments may fail to be retransmitted

Last Modified: Oct 16, 2023

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

Known Affected Versions:
11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1

Fixed In:
11.6.0, 11.5.2, 11.4.1 HF6, 11.3.0 HF9, 11.2.1 HF11

Opened: Feb 24, 2014

Severity: 3-Major

Related Article: K16537


Unacknowledged TCP segments are not retransmitted.


This issue causes connection timeouts.


Remote endpoint closes TCP window early and drops incoming TCP segment(s) from BigIP. Affects Standard TCP virtuals.


This issue has no workaround.

Fix Information

Unacknowledged TCP segments are re-transmitted upon re-opening of window.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips