Multicast only fast re-route over remote loop-free alternate backup path

A network device comprising:

• a processor configured to:
• receive a join request for a multicast group from one or more receivers,
• send a first multicast routing protocol control message including the join request to a first upstream neighbor network device along a primary path toward a source of the multicast group, wherein the primary path comprises a direct link between the network device and the first upstream neighbor network device, and
• wherein the network device is configured with multicast only fast re-route (MoFRR), send a second multicast routing protocol control message including the join request to a second upstream neighbor network device along a remote loop-free alternate (RLFA) backup path toward a RLFA network device, the second control message further including a different message type than the first control message and an address of the RLFA network device, wherein the RLFA backup path comprises a label switching path (LSP) between the network device and the RLFA network device that traverses the second upstream neighbor network device and a direct link between the RLFA network device and the first upstream neighbor network device;
• and
• a forwarding engine configured to:
• receive, from the source of the multicast group, multicast data packets for the multicast group on at least one of the primary path or the RLFA backup path, and
• forward the multicast data packets for the multicast group toward the one or more receivers.

A method comprising:

• receiving, by a network device from a downstream neighbor network device, a first multicast routing protocol control message including a join request for a multicast group, a first message type, and an address of a remote loop-free alternate (RLFA) network device in a RLFA backup path, wherein the RLFA backup path comprises a label switching path (LSP) between the downstream neighbor network device and the RLFA network device that traverses one or more intermediate network devices and a direct link between the RLFA network device and an upstream neighbor network device toward a source of the multicast group;
• based on the network device not being the RLFA network device identified in the first control message, generating, by the network device, a second multicast routing protocol control message including the join request, the first message type, and the address of the RLFA network device, and sending the second control message along the RLFA backup path toward the RLFA network device;
• based on the network device being the RLFA network device identified in the first control message, generating, by the network device, a third multicast routing protocol control message including the join request and a second message type that is different than the first message type, and sending the third control message along the RLFA backup path toward the source of the multicast group;
• receiving, by the network device from the source of the multicast group, multicast data packets for the multicast group on the RLFA backup path;
• and
• forwarding, by the network device, the multicast data packets for the multicast group to the downstream neighbor network device along the RLFA backup path.

A network device comprising:

• a processor configured to:
• receive, from a downstream neighbor network device, a first multicast routing protocol control message including a join request for a multicast group, a first message type, and an address of a remote loop-free alternate (RLFA) network device in a RLFA backup path, wherein the RLFA backup path comprises a label switching path (LSP) between the downstream neighbor network device and the RLFA network device that traverses one or more intermediate network devices and a direct link between the RLFA network device and an upstream neighbor network device toward a source of the multicast group,
• based on the network device not being the RLFA network device identified in the first control message, generate a second multicast routing protocol control message including the join request, the first message type, and the address of the RLFA network device, and send the second control message along the RLFA backup path toward the RLFA network device, and
• based on the network device being the RLFA network device identified in the first control message, generate a third multicast routing protocol control message including the join request and a second message type that is different than the first message type, and send the third control message along the RLFA backup path toward the source of the multicast group;
• and
• a forwarding engine configured to:
• receive, from the source of the multicast group, multicast data packets for the multicast group on the RLFA backup path, and
• forward the multicast data packets for the multicast group to the downstream neighbor network device along the RLFA backup path.