Bug ID 487554: System might reuse TCP source ports too quickly on the server side.

Last Modified: Apr 10, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP PEM(all modules)

Known Affected Versions:
11.5.0, 11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 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, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4

Fixed In:
12.0.0, 11.6.0 HF5, 11.5.2

Opened: Oct 29, 2014
Severity: 3-Major
Related AskF5 Article:
K41581381

Symptoms

System might reuse TCP source ports too quickly on server side when dag hash is ip-only and sourceport mode is set to change.

Impact

Conflicting flows result in connections being reset.

Conditions

This occurs when the dag-cmp hash is ip-only, and the virtual server or PEM-forwarding endpoints sourceport mode is set to change. The BIG-IP system might reuse some TCP source ports on the server side.

Workaround

This issue has no workaround at this time.

Fix Information

In this release, reuse of TCP source ports is sequential, which eliminates the issue of TCP source ports being used too quickly on the server side.

Behavior Change