Bug ID 726176: Platforms using RSS hash reuse source port too rapidly when the FastL4 virtual server is set to source-port preserve

Last Modified: Jul 12, 2023

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

Known Affected Versions:
13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,, 14.0.0,,,,,, 14.0.1,, 14.1.0,,,,,, 14.1.2,,, 15.0.0, 15.0.1

Fixed In:

Opened: Jun 29, 2018

Severity: 3-Major


The BIG-IP system running RSS DAG hash attempts to reuse ports while pool members remain in a TIME_WAIT state and are unable to process new connections.


Traffic throughput may be degraded.


This issue occurs when all of the following conditions are met: -- You are running on a BIG-IP platform using RSS DAG hash, for instance, Z100 and 2000/4000-series hardware platform -- You have the FastL4 profile associated with a virtual server. -- The virtual server is configured with source-port preserve.


Set source-port to change.

Fix Information

Platforms running RSS DAG hash now reuse source port at the correct rate when virtual server sets source-port preserve.

Behavior Change

Guides & references

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