User's Manual

Components 543
find that you have to configure the VLAN on the same set of inter-switch
links, you could save the switches and ports involved as a template and
open this template whenever a new VLAN needs to be created.
When you click the OK button in the Selection Editor dialog box, 3Com
Network Director will perform some checks on the selected switch ports.
If a port has been selected as untagged and the port is already an
untagged member of a VLAN, 3Com Network Director will warn you that
you may lose contact with any devices that are currently connected to this
port. However, 3Com Network Director will not prevent you from
proceeding with this port selection.
3Com Network Director will also check for ports that have been selected
as tagged that 3Com Network Director thinks should be untagged. By
default, 3Com Network Director will assume that the following types of
switch port should be untagged:
■ Switch ports connected to devices that are not switches e.g.
end-stations.
■ Switch ports that are currently unconnected.
Again, 3Com Network Director will warn you if have selected ports of
these types to be tagged, but will not prevent you from proceeding with
this selection.
Checking VLAN connectivity
When you click the Next button in the previous wizard stage, 3Com
Network Director will check that there are no gaps in the list of selected
switches and ports. For the VLAN to be complete, 3Com Network
Director assumes that it should be possible to trace a path from any
switch port in the selection to any other switch port in the selection, and
all ports in this path should also be in the current selection. If this is not
the case, 3Com Network Director will display the additional ports that
need to be selected to fill in any gaps.
For example, in the network below, if the Create VLAN wizard was
launched with only the switch1-switch2 link and the switch4-PC link
selected, 3Com Network Director would spot the fact that there was a
gap in the VLAN. So for complete connectivity, the ports connecting
switch2 and switch3, and the ports connecting switch3 and switch4,
should also be added to the new VLAN.