Which tunnel type between two WLCs is required to support inter-controller roaming?

Inter-controller roaming, where a client moves between access points associated with different Wireless LAN Controllers (WLCs), requires a mobility tunnel. This tunnel facilitates the seamless transfer of client context (e.g., security associations, QoS parameters) between the WLCs, ensuring the client's session remains active without reauthentication. CAPWAP (Control and Provisioning of Wireless Access Points) and LWAPP (Lightweight Access Point Protocol) are protocols used for communication between an AP and a WLC, not directly for inter-controller roaming. IPsec is a security protocol that can encrypt traffic but doesn't inherently provide the client context transfer mechanism needed for mobility.