Bug ID 563444: vCMP guest cluster may have two primaries due to partial partitioning of the management backplane network on one cluster member

Last Modified: Jun 30, 2021

Bug Tracker

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

Known Affected Versions:
11.4.1, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3,,,,,,,, 12.1.4,, 12.1.5,,,, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Fixed In:

Opened: Dec 16, 2015
Severity: 3-Major


The management backplane network on one cluster member of a vCMP guest may partially malfunction in that multicast packets are able to be sent out of the cluster member but incoming multicast packets from the peer members are dropped. This results in the cluster becoming "split-brained" and having two primary members; the original primary remains so while the isolated member also elects itself as a primary.


Dataplane traffic remains unaffected. However, configuration changes will not propagated to the isolated cluster member, and stats will not be synced from the isolated cluster member. Furthermore, if the cluster is the active unit in an HA pair, this may result in a failover not occurring as expected due to the technical nature of the malfunction.


This issue only occurs on vCMP guest clusters and has been found to only happen in extremely rare cases.


To resolve the issue, reboot the cluster member whose management backplane has malfunctioned.

Fix Information


Behavior Change