1. A switch, comprising: one or more ports; processing circuitry; a storage device coupled to the processing circuitry and storing instructions which when executed by the processing circuitry cause the processing circuitry to perform a method, the method comprising: extracting an identifier of a root of a spanning tree and a first path cost to the root from a first message received via a local edge interface; extracting the identifier of the root and a second path cost to the root from a second message received from a second switch, wherein the switch and the second switch are members of a first fabric switch, wherein a fabric switch includes a plurality of switches operating as a single switch; assigning an interface state to the local edge interface based on the first and second path costs.