SPBM Multicast FIB

Multicast FIB

SPBM runs all pair Dijkstras to produce the multicast FIB. The computing node loops through each node to run Dijkstra using that node as the root, and then prunes paths to only keep the shortest paths. The computing node then computes the intersection of the set of I-SIDs for which the root node transmits, with the set of I-SIDs for which the path endpoints receive.

The multicast addresses are built out of two pieces: the SPBM Node Nickname and the I-SID ID converted to hexadecimal format to form the multicast MAC address.

|----------------------------|---------------------------------|
       nickname|0x30000 		          hexadecimal I-SID

For example, if the nickname is 0.00.10 and the I-SID is 100 (0x64), the multicast address is 03:00:10:00:00:64.

The following text shows an example of the multicast FIB.

Switch:1(config)#show isis spbm multicast-fib

==========================================================================================
                              SPBM MULTICAST FIB ENTRY INFO
==========================================================================================
MCAST DA           ISID     BVLAN SYSID       HOST-NAME   OUTGOING-INTERFACES  INCOMING
                                                                                INTERFACE
------------------------------------------------------------------------------------------
03:00:07:e4:e2:02  15000066 1001  0077.0077.0077 Switch-25  1/33            MLT-2
03:00:08:e4:e2:02  15000066 1001  0088.0088.0088 Switch-33  1/50,1/33       40.40.40.40
03:00:41:00:04:4d  1101     4058  00bb.0000.4100 Switch-1(*)1/3,1/49,0.0.0.0 Tunnel_to_HQ
03:00:41:00:04:4f  1103     4058  00bb.0000.4100 Switch-1(*)1/3,1/49,0.0.0.0 cpp
------------------------------------------------------------------------------------------
Total number of SPBM MULTICAST FIB entries 4
------------------------------------------------------------------------------------------