Helper-map for Broadcast to multicast conversion and vice versa. ---------------------------------------------------------------- The following is an example which illustrates the use of the helper-map command at the first-hop and the last-hop, to convert a broadcast stream directed to port 2000 to a multicast stream and back. On the first hop router ----------------------- The following example converts broadcast streams to port 2000 to a multicast stream(G = 224.5.5.5) int < ... > /* incoming interface of broadcast stream */ ip multicast helper-map broadcast 224.5.5.5 101 ip pim dense ..... ip forward-protocol udp 2000 access-list 101 permit udp any any eq 2000 access-list 101 deny udp any any On the last hop router --------------------- int <...> /* incoming interface of multicast stream */ ip multicast helper-map 224.5.5.5 178.21.34.255 101 ip pim dense ..... ip forward-protocol udp 2000 access-list 101 permit udp any any eq 2000 access-list 101 deny udp any any Note: o Configuring the multicast helper map command (to convert multicast to broadcast) will also automatically configure "ip igmp join-group " on the interface. The router must be joined to the multicast group to be translated to a broadcast address. o In Cisco IOS 12.0, it is necessary to configure the interface command "ip directed-broadcast" along with helper-map command. By default, it is turned off.