Bug ID 716492: Rateshaper stalls when TSO packet length exceeds max ceiling.

Last Modified: Feb 20, 2019

Bug Tracker

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

Known Affected Versions:
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, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Fixed In:
14.1.0

Opened: Apr 23, 2018
Severity: 3-Major
Related AskF5 Article:
K59332523

Symptoms

If a TCP Segmentation Offload (TSO) packet length exceeds the rateshaper's max ceiling, it causes the flow to stall.

Impact

The flow stalls. Subsequent flows cannot go to the rateshaper from that particular tmm.

Conditions

TSO packet length exceeds the rateshaper's configured max ceiling.

Workaround

If you are running BIG-IP software v12.1.3.2 (or later) or v13.1.0(.x), you can use the following workaround: There is a sys db variable called 'rateshaper.cmpdivide', which is enabled by default. When enabled, the system internally divides the bandwidth (rate/ceiling/burst) between the available tmm cores. If this issue occurs, set 'rateshaper.cmpdivide' to enabled. There is no workaround for other versions.

Fix Information

Rateshaper no longer stalls when TSO packet length exceeds max ceiling.

Behavior Change