Home » Cisco » 350-080 » When using Overlay Transport Virtualization (OTV), how do L2 multicast frames traverse the overlay?
When using Overlay Transport Virtualization (OTV), how do L2 multicast frames traverse the overlay?
A. The L2 multicast frames are encapsulated in an OTV packet using the configured control-group multicast address for transport
B. The L2 multicast frames are dropped because multicast cannot be carried across the overlay
C. The L2 multicast frames are encapsulated in an OTV packet using the configured data-group multicast address for transport
D. The L2 multicast frames are forwarded natively across the overlay based on their multicast IDs
Correct Answer: C
Explanation/Reference:
Explanation:
The OTV internal interfaces carry the VLANs to be extended and the OTV site VLAN (used within the data center to provide multihoming). They behave as regular Layer 2 switch port trunk interfaces; in fact, they send, receive, and process the Spanning Tree Protocol BPDUs as they would on a regular LAN bridge device.
The overlay interfaces encapsulate Layer 2 frames in IP unicast or multicast packets and are logical Ethernet41ess, multicast-capable interfaces.
The join interfaces are point-to-point routed interfaces that are used by the OTV edge devices to join the overlay network. Currently, the OTV implementation uses the IP address of the physical join interface to advertise reachability of MAC-addresses present in the site. In a future release, the plan is to use the loopback address for this purpose.
The same OTV VDCs can be used by multiple VDCs deployed at the aggregation tier, as well as by other Layer 2 switches connected to the OTV VDCs. This is done by configuring multiple OTV overlays. It’s important to note that the extended VLANs within these multiple overlays should not overlap.
Reference: http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Data_Center/DCI/whitepaper/DCI3_OTV_Intro/DCI_1.html
