There are two Frame Relay interface types:
- Multi-Point – Requires the use of the broadcast keyword, and split horizon must be disabled at the hub (for partial mesh topologies). Physical interfaces or logical subinterfaces may be used; a shared network ID requires physical mapping of remote addresses to local DLCIs.
- Point-to-Point – Emulate physical point-to-point links, and can pass broadcast or multicast traffic without additional configuration. Most applicable to hub-and-spoke topologies.
To send multicast packets over Frame Relay virtual circuits, map with the following command:
frame-relay map ip <ip address> <dlci> broadcast
Split horizon does not need to be disabled on P2P links.
Stuck-in-Active: Journal of an IT-Network Administrator 