System and method for IP multicast

A method for routing multicast packets, the method comprising:

• receiving at an inbound interface on a switch/router a multicast packet, wherein the multicast packet comprises source (S) and group (G) addresses;
• determining whether the S and G addresses are mapped to an outbound interface in an Outgoing Interface List (OIL) table;
• obtaining from the OIL table a first routing entry for a first outbound interface and a second routing entry for a second outbound interface, wherein the first routing entry comprises a partial match of a first address of the first outbound interface and the S and G addresses and the second routing entry comprises a partial match of a second address of the second outbound interface and the S and G addresses, when the S and G addresses are not mapped to an outbound interface in the OIL table;
• determining which of the first and second routing entries comprises a longest partial match of the respective first and second outbound interface addresses and the S and G addresses;
• and
• forwarding the multicast packet over the determined first or second outbound interface.

A method for routing multicast packets, the method comprising:

• receiving at an inbound interface on a switch/router a multicast packet, wherein the multicast packet comprises source (S) and group (G) addresses;
• determining whether the S and G addresses are mapped to an outbound interface in an Outgoing Interface List (OIL) table;
• obtaining from the OIL table a plurality of routing entries for outbound interfaces, wherein each routing entry comprises a partial match of an address of an outbound interface and the S and G addresses, when the S and G addresses are not mapped to any outbound interface in the OIL table;
• and
• forwarding the multicast packet over each outbound interface.