510 CHAPTER 13: V LAN M ANAGEMENTThe port on the Switch 3300 connected to the PS Hub has one VLAN,VLAN A, configured on it. Only the Switch 3300 has any awareness ofVLANs. The PS Hub and end stations are VLAN unaware devices. 3ComNetwork Director will infer that the PS Hub and the end-stations aremembers of VLAN A.If the user launched the Properties dialog box on one of the end-stations,it would be shown as being a member of VLAN A. See “Properties dialogbox” on page 524. Similarly if the user selected the Show VLANs menuoption. See “Show VLANs” on page 514 to view VLAN A, the PS Huband end stations would also be highlighted, not just the Switch 3300.The rules used for inferring VLAN membership for VLAN-unaware devicesare as follows.■ If a port on a VLAN-aware device is a member of VLAN A and alldevices hanging off the port are VLAN-unaware, then these deviceswill be assumed to be members of VLAN A as well. When working outthe bounds of the set of VLAN-unaware devices, 3Com NetworkDirector will stop when it reaches a router.■ 3Com Network Director can infer that a device is a member of morethan one VLAN.VLAN equivalenceAs well as inferring the VLAN membership of VLAN-unaware devices,3Com Network Director also attempts to match up VLANs configured onVLAN-aware devices, in order to determine whether any two VLANsconfigured on different devices are in fact the same VLAN. For example,with the network below:
