Bug ID 746620: "source-port preserve" does not work on BIG-IP Virtual Edition

Last Modified: Nov 22, 2021

Bug Tracker

Affected Product:  See more info
BIG-IP All(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: Oct 11, 2018
Severity: 3-Major


BIG-IP Virtual Edition uses RSS hashing for selecting TMMs which has the side effect of causing "source-port preserve" to reuse ports aggressively. This can ultimately lead to connection failures.


Connections may fail due to reusing ports too quickly.


BIG-IP virtual edition with "source-port preserve" configured on a fastl4 virtual server and VE configures RSS hash. VE will configure RSS hash if both the below conditions are met 1. VE supports RSS hash on the NIC. Currently, RSS is supported on ixlv and vmxnet3 NICs 2. The number of TMMs <= maximum number of queues supported by the NIC. For ixlv this is 4 and for vmxnet3 this is 8


On the Virtual Server, set source-port to "change".

Fix Information


Behavior Change