Step 2The OTV control protocol running on the left OTV edge device generates Hello packets that need to be sent to all other OTV edge devices. This is required to communicate its existence and to trigger the establishment of control plane adjacencies.
Step 3The OTV Hello messages need to be sent across the logical overlay to reach all OTV remote devices. For this to happen, the original frames must be OTV-encapsulated, adding an external IP header. The source IP address in the external header is set to the IP address of the Join interface of the edge device, whereas the destination is the multicast address of the ASM group dedicated to carry the control protocol. The resulting multicast frame is then sent to the Join interface toward the Layer 3 network domain.