Each port on a Cisco MDS 9000 Family switch is uniquely identified by its world wide names (WWNs), which include the switch MAC address and an identifier for each port. The principal switch selection and the allocation of domain IDs use the WWN to identify a specific port.
To add WWNs, perform the following steps.
The information pane of the Fabric Manager displays WWN information for multiple switches. The dialog box from the Device Manager displays WWN information for a single switch.