It should be noted that, in addition to assigning a hardwired GUID to each port on a CA or router, and to port 0 on a switch, the device designer also assigns the following hardwired identifiers to the device itself:
The device is assigned a hardwired, read-only 64-bit GUID as the NodeInfo.NodeGUID attribute element.
The device is assigned a hardwired, read-only text descriptor readable through the 64-byte NodeDescription attribute.