Bug ID 1992549: Virtual server with FastL4 will not have Timestamp option when syncookie mode activated

Last Modified: Jul 29, 2025

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

Known Affected Versions:
16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.5.0, 17.5.1

Opened: Jul 25, 2025

Severity: 3-Major

Symptoms

No timestamp option returned by BIG-IP on SYN-ACK

Impact

Lower performance for tcp

Conditions

This occurs on a FastL4 virtual server where syncookie protection mode has been activated.

Workaround

If possible, use standard virtual server

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips