In one of the Cisco docs, I read:
The FabricPath Layer 2 gateway switch will automatically propagate Topology Change Notifications (TCNs) on all its CE (Classical Ethernet) interfaces. The Layer 2 IS-IS messages will carry TCNs across the FabricPath network if proper STP configuration is made on the different switches.
- Why do the TCNs need to be carried across the Fabric path network? Is the writer trying to convey that there are two separate STP domains connected via the Fabric path network?
- Do I need to know the underlying details of ISIS to understand fabric path? I mean, I just want to know enough to drive the car but not intend to know the working of the car engine.