The underlay interface carrying the traffic can be any physical port or port-channel Layer 3 interface between the MCT peers. VE's are not supported. By default, all MCT VLANs or bridge domains (BDs) are extended to the MCT peer.
By default, VLAN-VNI mapping is automatically configured for the ICL VxLAN tunnel. Since a single VLAN-VNI mapping domain is supported, any change to this mapping under the overlay gateway changes the mapping for the ICL and temporarily affects its traffic.