Bug ID 442098: Avoid Head-of-line blocking by enabling egress queue discard limits.

Last Modified: Jul 18, 2026

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

Known Affected Versions:
11.5.1, 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, 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, 11.5.10, 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, 11.6.5.1, 11.6.5.2, 11.6.5.3

Opened: Jan 03, 2014

Severity: 2-Critical

Related Article: K16373

Symptoms

For a lossless mode switch configuration associated with ingress buffering, there is a potential for the switch to experience head-of-line blocking during periods of egress contention/congestion, where lower ingress limits may result in ingress dropping of sensitive traffic. This affects the following platforms; PB200, 11000, 11050, B2100, 5000, 7000.

Impact

Traffic over the high speed 1 GB link gets impacted by buffering on the low speed 10 MB link.

Conditions

This might occur when the system sends logging data at a speed higher than the physical interface to the logging server can support, for example 50Mbps of HSL to a 10Mbps ethernet link.

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips