Bug ID 625198: TMM might crash when TCP DSACK is enabled

Last Modified: Oct 06, 2020

Bug Tracker

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

Known Affected Versions:
11.2.1, 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, 11.5.10, 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, 11.6.0, 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, 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

Fixed In:
13.0.0, 12.1.2 HF1, 11.6.2, 11.5.7

Opened: Oct 27, 2016
Severity: 2-Critical

Symptoms

TMM crashes

Impact

Traffic disrupted while tmm restarts.

Conditions

All of the below are required to see this behavior: DSACK is enabled MPTCP, rate-pace, tail-loss-probe, and fast-open are disabled. cmetrics-cache-timeout is set to zero; congestion control is high-speed, new-reno, reno, or scalable; AND Nagle is not set to 'auto'. an iRule exists that changes any of the conditions above besides DSACK. various client packet combinations interact in certain ways with the iRule logic.

Workaround

Change any of the conditions above.

Fix Information

TCP maintains state appropriately to avoid crash.

Behavior Change