Bug ID 698462: TCP timestamp rewrite mode not working on the client side of ePVA offloaded connections

Last Modified: Sep 06, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP LTM(all modules)

Known Affected Versions:
10.2.2, 10.2.3, 10.2.4, 11.0.0, 11.1.0, 11.2.0, 11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.5.3 HF2, 11.5.4, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1, 11.6.1 HF1, 11.6.1 HF2, 11.6.2, 11.6.2 HF1, 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, 12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 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, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.4, 14.1.0.5, 14.1.0.6, 14.1.2, 15.0.0, 15.0.1

Opened: Dec 11, 2017
Severity: 3-Major
Related AskF5 Article:
K29235166

Symptoms

When the tcp-timestamp-mode is set to 'rewrite', not the default 'preserve', the client side TSecr is not set correctly for the FIN packets. When the flow is evicted due to FIN processing in ePVA, the process copies the timestamp from the server sending the FIN/ACK. This unexpected behavior causes the TCP client to halt at the FIN-WAIT-2 because the client thinks the FIN/ACK from the BIG-IP system includes illegitimate timestamp options, and drops it.

Impact

TCP client cannot handle the FIN packets properly, causing connection issues.

Conditions

-- tcp-timestamp-mode is set to 'rewrite'. -- FastL4 profile. -- Systems with ePVA feature support.

Workaround

Use the default 'preserve' mode for FastL4 profiles.

Fix Information

None

Behavior Change