Bug ID 614410: Unexpected handling of TCP timestamps in HA configuration

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 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, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Fixed In:
13.1.0

Opened: Sep 03, 2016

Severity: 3-Major

Symptoms

Despite TCP timestamps being configured, the BIG-IP system fails to present timestamp option during TCP negotiation. The BIG-IP system calculates invalid round trip time, which might result in delayed retransmission.

Impact

Retransmission timeout (RTO) value may be skewed. Segments that are subject to RTO might take up to 64 segments to retransmit.

Conditions

This occurs when the following conditions are met: - Virtual server configured with a TCP profile with timestamps enabled. - Virtual server configured with connection mirroring.

Workaround

None.

Fix Information

TCP timestamps are negotiated when connection mirroring is enabled and the following system-wide db variable is enabled: tmsh modify sys db tm.tcptimestampmirror value enable

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips