Cisco Updated 300-425 Exam Questions and Answers by moses

Mobility domains and mobility groups are concepts used in wireless networking to manage client roaming and security contexts. When Wireless LAN Controllers (WLCs) are in the same mobility domain, they can communicate with each other, allowing clients to roam seamlessly between APs managed by different controllers. Mobility groups further refine this by constraining the distribution of a client’s security context, which includes authentication and encryption keys, and by managing AP failover between controllers. This ensures that a client can maintain a secure and stable connection as they move throughout the network.

Guest anchoring requires mobility tunnels to be established between the foreign and anchor WLCs. For these tunnels to function, the firewall must allow specific ports for communication. UDP port 16666 is the port used for mobility traffic in Cisco wireless networks, and if it is not allowed through the firewall, MPING and mobility tunnels will fail. References: CCNP Enterprise Wireless Design ENWLSD 300-425 and Implementation ENWLSI 300-430 Official Cert Guide Premium Edition and Practice

The issue where APs failed over to the tertiary controller instead of the secondary controller during a controller failure is likely due to the secondary controller being at capacity. When a controller reaches its maximum capacity, it cannot accept any additional APs, causing them to failover to the next available controller in the high availability configuration.