A. IGMP is not synchronized between vPC peers
B. Cisco Fabric Service carries IGMP entries across the vPC peer link
C. IP ARP synchronization under the vPC domain configuration also synchronizes IGMP
D. IGMP is flooded to the L2 domain， and there is no need to synchronize it between vPC peers

A. The OTV control-plane protocol uses the IS-IS protocol to establish adjacencies and exchange MAC reachability across the overlay network. You must enable IS-IS with the feature isis command before OTV adjacencies can be established.
B. OTV uses an SSM group range for neighbor discovery and to exchange MAC reachability with other OTV edge peers.
C. The OTV join interface is a routed uplink interface on the edge device used to physically join the overlay network.
D. The OTV internal interface encapsulates the site Layer 2 frames in IP unicast or multicast packets that are then sent to the other sites.