Bug ID 527537: CGNAT experiences increased CPU utilization with a high concurrent connection load and persistence enabled

Last Modified: Apr 28, 2025

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

Known Affected Versions:
11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5

Fixed In:
12.0.0, 11.6.0 HF6

Opened: Jun 11, 2015

Severity: 3-Major

Symptoms

Elevated CPU with CGNAT when carrying the same load between 11.5 and 11.6

Impact

Elevated CPU = reduced capacity

Conditions

CGNAT lsn-pools high number of concurrent connections persistence = address-port and/or inbound enabled

Workaround

None

Fix Information

Change the sessionDB sweeper to reduce the amount of work it does managing large bins.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips