Bug ID 484861: A standby-standby state can be created when auto failback acts in a CRC disagreement scenario

Last Modified: Sep 13, 2023

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

Known Affected Versions:
11.5.1 HF1, 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, 11.5.1 HF10, 11.5.1 HF11, 11.5.2 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.2.1, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.6.0, 11.6.1, 11.6.2, 11.6.3,,,,, 11.6.4, 11.6.5,,,, 12.1.0 HF1, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.0.0, 11.6.0 HF5, 11.5.4, 11.4.1 HF9

Opened: Oct 16, 2014

Severity: 3-Major

Related Article: K16919


A standby-standby state can occur after a failback if there is a CRC disagreement between peers.


It's a site down situation as all the objects in the traffic group will become unreachable.


HA pair using auto failback. There must be a CRC disagreement between peers. The failback preferred system must have a lower traffic group score than its peers. NOTE: CRC disagreements may lead to other issues and the customer is strongly advised to sync the devices to remove the disagreement.


Sync devices to remove the CRC disagreement.

Fix Information

Ensure that the preferred system goes active after auto failback, even if its traffic group score is lower than that of its peers.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips