After adding four new switches to a Brocade VCS fabric running TRILL, you determine that one of
the switches in the fabric is not allowed to join. What are two reasons why this has occurred?
(Choose two.)

A.
The vcs enable command is not present in the configuration.

B.
23 RBridges are defined in the fabric.

C.
The switch has the same RBridge ID as another device.

D.
The switch has the same VCS ID as another device.