MULTICAST ONLY FAST RE-ROUTE OVER REMOTE LOOP-FREE ALTERNATE BACKUP PATH

摘要

Techniques are described for enhancements to Protocol Independent Multicast (PIM) to support multicast only fast re-route (MoFRR) over a remote loop free alternate (RLFA) backup path in a network. This disclosure describes a modified PIM control message having a new PIM message type and an additional field to indicate an address of a RLFA network device in the RLFA backup path. According to techniques of this disclosure, network devices along the RLFA backup path are configured to forward the modified PIM control message toward the RLFA network device instead of toward a source of a requested multicast group. When the RLFA network device receives the modified PIM control message, the RLFA network device is configured to forward a conventional PIM control message towards the source of the requested multicast group. In this way, PIM can be used to provide MoFRR over a RLFA backup path.

主权项

1. A method comprising:
receiving, by a network device configured with multicast only fast re-route (MoFRR), a join request initiated by one or more receivers for a multicast group; sending, by the network device, a first protocol independent multicast (PIM) control message including the join request to a first upstream network device along a primary path toward a source of the multicast group; sending, by the network device, a second PIM control message including the join request to a second upstream network device along a remote loop-free alternate (RLFA) backup path toward a RLFA network device, the second PIM control message further including a different PIM message type than the first PIM control message and an address of the RLFA network device; receiving, by the network device 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 forwarding, by the network device toward the one or more receivers, the multicast data packets for the multicast group.