Refer to the exhibit. An engineer determined that during a recent controller failure, some APs did not failover to their secondary controller based on the network design, which has sufficient licenses for all APs. The controllers are not in a mobility group but have A records for their hostnames in DNS. Which setting needs to be addressed?
The controllers must be in the same mobility group to enable seamless AP failover. The mobility group ensures that access points can properly communicate and authenticate with multiple controllers, which is a critical requirement for failover operations. Without being in the same mobility group, the access points may not recognize the secondary controller, resulting in failure to failover during a primary controller outage.
Correct A
The controllers do not have to be in the same mobility group. Priority is not the issue here either. In the guides, you will not find any references about DNS in the HA configuration. I would suggest answer B in this case. https://www.cisco.com/c/en/us/td/docs/wireless/controller/7-4/configuration/guides/consolidated/b_cg74_CONSOLIDATED/m_configuring_backup_controllers.pdf
If the secondary WLC IP is wrong, why should only "some" APs not failover? If the secondary IP is wrong, the failover shouldnt work for all APs .. or am i misunderstanding something here?