The unicast computation runs a single Dijkstra (unlike all pair Dijkstras for multicast). SPBM produces only one Shortest Path First (SPF) tree and the tree is rooted on the computing node.
The unicast computation generates an entry for each node in the network. The Destination Address (DA) for that entry is the system-id of the node. In addition, if a node advertises MAC addresses other than the system-id, each MAC address has an entry in the unicast FIB table, and the shortest path to that MAC should be exactly the same as the path to the node.
Unicast FIB entries are installed to the vlan-fdb table.
The following text shows an example of the unicast FIB.
Switch:1# show isis spbm unicast-fib
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SPBM UNICAST FIB ENTRY INFO
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DESTINATION BVLAN SYSID HOST-NAME OUTGOING COST AREA AREA-NAME
ADDRESS INTERFACE
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00:16:ca:23:73:df 1000 0016.ca23.73df SPBM-1 1/21 10 HOME area-9.00.02
00:16:ca:23:73:df 2000 0016.ca23.73df SPBM-1 1/21 10 HOME area-9.00.02
00:18:b0:bb:b3:df 1000 0018.b0bb.b3df SPBM-2 MLT-2 10 HOME area-9.00.02
00:14:c7:e1:33:e0 1000 0018.b0bb.b3df SPBM-2 MLT-2 10 HOME area-9.00.02
00:18:b0:bb:b3:df 2000 0018.b0bb.b3df SPBM-2 MLT-2 10 HOME area-9.00.02
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Home: Total number of SPBM UNICAST FIB entries 5
Remote: Total number of SPBM UNICAST FIB entries 0
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