Fast reroute for multiple label switched paths sharing a single interface

A method comprising:

• maintaining routing information in accordance with a topology of a network with a routing protocol of a router;
• with a packet-forwarding engine (PFE) of the router, outputting multi-protocol Label Switching (MPLS) packets associated with a plurality of label switched paths (LSPs) onto a first physical link using a first interface port, wherein the first interface port is configured to engage the first physical link;
• programming a packet-forwarding integrated circuit (IC) of the PFE to internally store a hardware version of a forwarding information base (FIB) in accordance with the routing information, the hardware version of the FIB including a plurality of entries addressable by the packet-forwarding IC, the entries identifying pairs of primary forwarding next hops and backup forwarding next hops for the LSPs, wherein the packet-forwarding IC comprises a control logic module and internal selector block configured to produce a value indicating a state of the first physical link,
• wherein the selector block of the packet-forwarding IC is configured to output one of the primary forwarding next hop and the backup forwarding next hop of the entries for forwarding the MPLS packets based on the value indicating the state of the first physical link in response to the packet-processing engine addressing one of the entries of the FIB for the LSPs;
• and
• forwarding packets with the PFE to the one of the primary forwarding next hop and the backup forwarding next hop that is output by the selector block.

A non-transitory computer-readable medium comprising instructions for causing a programmable processor to:

• with a packet-forwarding engine (PFE) of the router, output multi-protocol Label Switching (MPLS) packets associated with a plurality of label switched paths (LSPs) onto a first physical link using a first interface port, wherein the first interface port is configured to engage the first physical link;
• program a packet-forwarding integrated circuit (IC) of the PFE to internally store a hardware version of a forwarding information base (FIB) in accordance with routing information maintained in accordance with a topology of a network, the hardware version of the FIB including a plurality of entries addressable by the packet-forwarding IC, the entries identifying pairs of primary forwarding next hops and backup forwarding next hops for the LSPs, wherein the packet-forwarding IC comprises a control logic module and internal selector block configured to produce a value indicating a state of the first physical link,
• wherein the selector block of the packet-forwarding IC is configured to output one of the primary forwarding next hop and the backup forwarding next hop of the entries for forwarding the MPLS packets based on the value indicating the state of the first physical link in response to the packet-processing engine addressing one of the entries of the FIB for the LSPs;
• and
• forward packets with the PFE to the one of the primary forwarding next hop and the backup forwarding next hop that is output by the selector block.