Method and system for protocol independent multicasting in multichassis link aggregation domains

A multichassis link aggregation (MLAG) domain, comprising:

• a first MLAG peer configured to:
• receive, from a first external device, an IP multicast packet associated with a first Virtual Local Area Network (VLAN),
• bridge a copy of the IP multicast packet to all external devices in the MLAG domain, other than the first external device, associated with the first VLAN,
• apply a first routing rule to the first IP multicast packet to obtain a new IP multicast packet associated with a second VLAN,
• bridge a copy of the new IP multicast packet to each of:
• all external devices, associated with the second VLAN that are directly connected to the first MLAG peer and a second MLAG peer via a peer link;
• and
• the second MLAG peer configured to:
• receive, via the peer link, one copy of the new IP multicast packet associated with the second VLAN;
• apply a second routing rule to the one copy of the new IP multicast packet associated with the second VLAN to obtain a second new IP multicast packet associated with a third VLAN;
• and
• wherein the first MLAG peer is further configured to:
• receive, via the peer link, the second new IP multicast packet associated with the third VLAN;
• and
• bridge a copy of the second new IP multicast packet associated with the third VLAN to all external devices associated with the third VLAN that are singly connected to the first MLAG peer.

A method for processing Internet Protocol (IP) multicast packets in a multichassis link aggregation (MLAG) domain, the method comprising:

• receiving, from a first external device, a first IP multicast packet associated with a first Virtual Local Area Network (VLAN) by a first MLAG peer in the MLAG domain;
• bridging a copy of the IP multicast packet to all external devices in the MLAG domain, other than the first external device, associated with the first VLAN;
• applying, on the first MLAG peer, a first routing rule to the first IP multicast packet to obtain a new IP multicast packet associated with a second VLAN;
• bridging a first copy of the new IP multicast packet associated with the second VLAN to all external devices, associated with the second VLAN, that are directly connected to the first MLAG peer;
• forwarding, via a peer link, a second copy of the new IP multicast packet associated with the second VLAN to the second MLAG peer, wherein the second MLAG peer applies a second routing rule to the second copy of the new IP multicast packet associated with the second VLAN to obtain a second new IP multicast packet associated with a third VLAN, wherein a copy of the second new IP multicast packet associated with the third VLAN is forwarded across the peer link;
• receiving, via the peer link, a copy of the second new IP multicast packet associated with the third VLAN from the second MLAG peer;
• and
• bridging a copy of the second new IP multicast packet associated with the third VLAN to all external devices associated with the third VLAN that are singly connected to the first MLAG peer.