Bug ID 709610: Subscriber session creation via PEM may fail due to a RADIUS-message-triggered race condition in PEM

Last Modified: Oct 16, 2023

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

Known Affected Versions:
12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 14.0.0, 14.0.0.1, 14.0.0.2

Fixed In:
14.1.0, 14.0.0.3, 13.1.0.6, 12.1.3.6

Opened: Mar 09, 2018

Severity: 3-Major

Symptoms

Session replacement fails as a result of a race condition between multiple RADIUS Accounting Start and Stop messages for the same subscriber.

Impact

Subscriber session creation via PEM may fail.

Conditions

This occurs when the following conditions are met: -- These SysDB variables are set as follows: sys db tmm.pem.session.radius.retransmit.timeout { value "0" } sys db tmm.pem.session.provisioning.continuous { value "disable" } -- Actions occur in the following order: 1. PEM receives RADIUS START with subscriber ID1 and IP1. 2. PEM receives RADIUS STOP with subscriber ID1 and IP1. 3. PEM receives RADIUS START with subscriber ID1 and IP2. 4. PEM receives RADIUS STOP with subscriber ID1 and IP2. -- The time interval between steps 1 and 2 is very small (less than ~1ms).

Workaround

There is no workaround other than to leave SysDbs variables set to the default values.

Fix Information

The system now handles PEM subscriber session updates properly, so this issue no longer occurs.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips