For devices for which OpenView can do 'smart' network (i.e, bridges and hubs) submap layout, this indicates which port this interface corresponds to on the device, according to following: Value Meaning < 255 Corresponds to a single port (the value '1' means 'port 1'). This type of value is typical for bridges. >= 255 Corresponds to a port group where the port group number is obtained by subracting 255 (the value '257' means 'port group 2'). This type of value is typical for hubs. Note: The port number OpenView uses will not necessarily match the vendor port number, but will start at 1 for the first non-port-group port. For example, if a hub has 12 EtherTwist ports, identified by the vendor as ports 1-12 and belonging to the same port group, and also an AUI port identified by the vendor as port 13, the AUI port will be port 1 for purposes of OpenView. For non-smart network connector devices, this value should be 0 and can be ignored.