Final answer:
Dynamic interfaces on WLCs are typically used for client data, user-defined, and for maintenance purposes. They must be reachable by other WLCs.
Step-by-step explanation:
Dynamic interfaces on WLCs (Wireless LAN Controllers) are typically used for client data, user-defined, and for maintenance purposes. These interfaces allow wireless clients to connect to the network and provide connectivity for various network services. They must be reachable by other WLCs in order to manage and control the wireless network effectively.