Bug ID 447390: FastL4 virtual servers with loose-close enabled do not pass traffic reliably

Last Modified: Oct 16, 2023

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

Known Affected Versions:
11.6.2 HF1, 11.3.0, 11.4.1

Fixed In:
11.6.0, 11.5.1 HF5, 11.4.1 HF6

Opened: Feb 05, 2014

Severity: 2-Critical

Related Article: K15231

Symptoms

FastL4 virtual servers with loose-close enabled do not pass traffic reliably.

Impact

This configuration might cause loss of connectivity. The majority of TCP handshakes fail, and messages in the ltm.log indicate 'Syncookie HW mode activated'.

Conditions

This occurs when assigning FastL4 with loose-close enabled to virtual servers.

Workaround

Do not enable loose-close on FastL4 virtual servers.

Fix Information

Loose-close no longer causes issues with traffic on FastL4 virtual servers.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips