User's Manual

510 CHAPTER 13: VLAN MANAGEMENT
The 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 of
VLANs. The PS Hub and end stations are VLAN unaware devices. 3Com
Network Director will infer that the PS Hub and the end-stations are
members 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 dialog
box” on page 524. Similarly if the user selected the Show VLANs menu
option. See “
Show VLANs” on page 514 to view VLAN A, the PS Hub
and end stations would also be highlighted, not just the Switch 3300.
The rules used for inferring VLAN membership for VLAN-unaware devices
are as follows.
■ If a port on a VLAN-aware device is a member of VLAN A and all
devices hanging off the port are VLAN-unaware, then these devices
will be assumed to be members of VLAN A as well. When working out
the bounds of the set of VLAN-unaware devices, 3Com Network
Director will stop when it reaches a router.
■ 3Com Network Director can infer that a device is a member of more
than one VLAN.
VLAN equivalence
As well as inferring the VLAN membership of VLAN-unaware devices,
3Com Network Director also attempts to match up VLANs configured on
VLAN-aware devices, in order to determine whether any two VLANs
configured on different devices are in fact the same VLAN. For example,
with the network below: