Bug ID 1284157: The fastL4 IP TOS mimic feature does not demote flows from PVA

Last Modified: Dec 28, 2023

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

Known Affected Versions:
14.0.0,,,,,, 14.0.1,, 14.1.0,,,,,, 14.1.2,,,,,,,,, 14.1.3,, 14.1.4,,,,,,, 14.1.5,,,,,, 15.0.0, 15.0.1,,,,, 15.1.0,,,,,, 15.1.1, 15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 15.1.9,, 15.1.10,,, 16.0.0,, 16.0.1,,, 16.1.0, 16.1.1, 16.1.2,,, 16.1.3,,,,,, 16.1.4,,, 17.0.0,,, 17.1.0,,,, 17.1.1,

Opened: Apr 03, 2023

Severity: 3-Major


The fastL4 IP TOS (type of service) "mimic" setting, where the BIG-IP reflects the TOS value received from a flow back towards that sender, is incompatible with the PVA acceleration hardware, but fails to demote the flow to be processed in software. As a result, for both ip-tos-to-client and ip-tos-to-server, the mimic setting is ineffective (behaves like pass-through) when a flow is PVA accelerated.


None, since flows with TOS adjustments are not supported in PVA anyway, and can not be hardware accelerated.


Fastl4 profile with ip-tos-to-client and/or ip-tos-to-server set to 'mimic' (this setting shows as the value 65534 in tmsh), and pva-acceleration is enabled.


Set pva-acceleration to 'none' in the fastl4 profile, so that flows using that profile are never eligable for PVA hardware acceleration

Fix Information


Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips