Bug ID 555039: VIPRION B2100: Increase egress traffic burst tolerance for dual CoS queue configuration

Last Modified: Sep 28, 2023

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

Known Affected Versions:
11.5.1 HF1, 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, 11.5.1 HF10, 11.5.1 HF11, 11.5.2 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 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, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 13.1.3.5, 13.1.3.6, 13.1.4, 13.1.4.1, 13.1.5, 13.1.5.1

Fixed In:
12.1.1, 11.6.1 HF1, 11.5.4 HF2

Opened: Oct 29, 2015

Severity: 3-Major

Related Article: K24458124

Symptoms

There is a high drop counts when running tmsh show net interface, and running tmctl -a drop_reason shows that a large number of drops are due to counters.rx_cosq_drop Smaller buffering alpha values are configured for egress buffering to allow an 8 HW CoS queue feature to correctly implement weight based egress dropping. This results in busy ports dropping more aggressively, although allowing more fair buffering amongst multiple active ports.

Impact

This results in busy ports dropping more aggressively. Note that using smaller values allows more fair buffering amongst multiple active ports, whereas higher values allow better burst absorption but less fair buffering.

Conditions

Higher traffic rates, which stress switch MMU buffering resources, might result in egress CoS queue drop on busy ports. This affects the BIG-IP 5000- and 7000 series platforms, and VIPRION B2100, B2150, and PB200 blades.

Workaround

None.

Fix Information

This release uses a larger alpha value for better burst absorption when the 8 hardware CoS queue feature is not enabled.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips