Which protocol is used in a DMVPN network to map physical IP addresses to logical IP addresses?

A customer has two Cisco 550B WLCs that manage all the access points in their network and provide N+1 redundancy and load balancing. The primary Cisco WLC has 60 licenses and the secondary Cisco WLC has 40. The customer wants to convert the N+1 model to an HA model and provide SSO. Configuration must be performed during a maintenance window. After performing all the configurations on both controllers, the config redundancy unit secondary command is issued on the secondary Cisco WLC and it fails. Which parameter needs to be in place to complete the configuration?

An engineer is designing an outdoor mesh network to cover several sports fields. The core of the network is located in a building at the entrance of a sports complex. Which type of antenna should be used with the RAP for backhaul connectivity?

Refer to the exhibit.

A client roams between two APs that are registered to two different controllers, where each controller has an interface in the client subnet. Both controllers are running AireOS. Which scenario explains the client roaming behavior?