Multiple domains in a multi-chassis system

Creation of port domains in a multi-chassis system. The multi-chassis system includes two or more chassis that each includes one or more blades. In one embodiment, a sync group of at least two chassis is created, typically by connecting the two or more chassis with an interconnection means such as a sync-cable. Then, two or more ports of the sync group are selected for inclusion in a port domain. The locations of the ports relative to each other is then determined. Finally, a port domain is generated based on the relative locations of the ports and port domain generation rules. If the ports are on separate chassis, then a global domain is generated if a predetermined number of global domains do not already exist and if the ports are on the same chassis, a local domain is generated regardless of the number of global domains.