multicast helper-map

The multicast helper-map command is similar in theory to how the unicast  helper-map works. With the IP helper map feature, IP broadcast packets, such as UDP based DHCP requests, have their destination addresses translated to a unicast address, such as the DHCP server. With the IP multicast helper map feature, IP broadcast packets have their destination addresses translated to a multicast address

Ø  With the IP helper map feature,

 IP broadcast packets, have their destination addresses translated to a unicast address

Ø  With the IP multicast helper map feature,

IP broadcast packets have their destination addresses translated to a multicast address