In a Cisco Mobility Express wireless deployment, which AP takes over if the primary AP fails?

In a Cisco Mobility Express environment, high availability is maintained through a Master AP election process. When the active Master AP fails or becomes unreachable, the subordinate APs initiate an election to select a new Master. The documented election algorithm for a failover event deterministically selects the subordinate AP that has the highest MAC address. This AP is then promoted to the Master role, taking over the wireless controller functions for the network to minimize downtime.

A. AP with highest IP address: The election process uses the static hardware MAC address for deterministic selection, not a potentially dynamic IP address.

B. AP with the lowest IP address: The election is not based on IP addresses. Furthermore, the selection criterion is the highest MAC address, not the lowest.

D. AP with highest controller up time: While uptime can indicate stability, it is not a factor in the Mobility Express Master AP failover election algorithm.

1. Cisco. (2020). Cisco Mobility Express Deployment Guide

Release 8.10. In the "High Availability" chapter

section "Master AP Election

" it states

"If the master AP goes down

a new master AP is elected from the group of subordinate APs. The subordinate AP with the highest MAC address is elected as the new master AP."

2. Cisco. (2020). Cisco Mobility Express User Guide

Release 8.10. In the "Configuring High Availability" chapter

it details the election process

confirming that upon failure of the master AP

"the subordinate AP with the highest MAC address is elected as the new master AP."