Bug ID 1088037: F5OS platform's cmp hash has been updated to handle only even ephemeral port numbers

Last Modified: Nov 20, 2025

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

Known Affected Versions:
15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7

Fixed In:
17.1.0, 16.1.4, 15.1.8

Opened: Mar 18, 2022

Severity: 3-Major

Symptoms

The F5OS platform's cmp hash has been updated to handle only even ephemeral port numbers. Use `tmsh list/modify net vlan vlan-XYZ dag-adjustment` to view or change the settings. The recommended and default setting is xor-5mid-xor-5low.

Impact

- only even TMM threads are processing traffic

Conditions

- only even port numbers are used (usually by a Linux client) - One of the following platforms: -- VELOS chassis -- r5000, r10000, or r12000-series appliance

Workaround

None

Fix Information

F5OS platform's cmp hash has been updated to handle only even ephemeral port numbers. Traffic should be distributed evenly between all TMM threads.

Behavior Change

F5OS platform's cmp hash has been updated to handle only even ephemeral port numbers. Traffic should be distributed evenly between all TMM threads.

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips