Figure 5 Tandem replication
SPBM multicast address
Each SPBM node has a multicast address for each SPB VSI. This multicast address consists of one shortest
path source identifier (SPSource ID) and one I-SID. The I-SID identifies an SPB VSI, and the SPSource ID
identifies the node as a multicast source in the SPB VSI.
By default, ISIS-SPB generates the SPSource ID automatically. You may choose to configure the SPSource
ID manually, but the SPSource ID must be unique throughout the SPBM network.
Figure 6 SPBM multicast address format
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