The FabricPath network uses the Layer 2 Intermediate System-to-Intermediate System (IS-IS) protocol to
forward traffic in the network using the FabricPath headers. Layer 2 IS-IS is different than Layer 3 IS-IS; the
two protocols work independently. Layer 2 IS-IS requires no configuration and becomes operational when
you enable FabricPath on the device. The frames carry the same FTag that is assigned at ingress throughout
the FabricPath network, and Layer 2 IS-IS allows all devices to have the same view of all the trees built by
the system. Known unicast traffic uses the Equal Cost Multipath Protocol (ECMP) to forward traffic throughout
the network. Finally, using ECMP and the trees, the system automatically load balances traffic throughout
the FabricPath network.
FabricPath provides configuration simplicity, scalability, flexibility, and resiliency within a Layer 2 domain.