3Com 3CRWX120695A, Reference Manual

Page: 190 / 570

190 C
HAPTER
5: C
ONFIGURING
WX S
YSTEM AND
A
DMINISTRATIVE
P
ARAMETERS
The WX switch through which a user is authenticated must be a member
of the Mobility Domain the user is assigned to. However, you are not
required to configure the VLAN on all WX switches in the Mobility
Domain. When a user roams to a WX switch that is not a member of the
VLAN the user is assigned to, the WX switch can tunnel traffic for the
user through another WX switch that is a member of the VLAN. (For
more information about Mobility Domains, see “Defining a Mobility
Domain” on page 88.)
Because the default VLAN might not be in the same subnet on each WX
switch, 3Com recommends that you do not rename the default VLAN or
use it for user traffic. Instead, configure other VLANs for user traffic.
Traffic Forwarding A WX switches traffic at Layer 2 among ports in the same VLAN. For
example, suppose you configure ports 4 and 5 to belong to VLAN 2 and
ports 6 and 7 to belong to VLAN 3. As a result, traffic between port 4 and
port 5 is switched, but traffic between port 4 and 6 needs to be routed by
an external router.
802.1Q Tagging The tagging capabilities of the WX are flexible. You can assign 802.1Q
tag values on a per-VLAN, per-port basis. The same VLAN can have
different tag values on different ports. In addition, the same tag value can
be used by different VLANs but on different network ports.
If you use a tag value, 3Com recommends that you use the same value as
the VLAN number. The WX switch does not require the VLAN number
and tag value to be the same, but some other vendors’ devices do.
Do not assign the same VLAN multiple times using different tag values to
the same network port. Although MSS does not prohibit you from doing
so, the configuration is not supported.
Creating a VLAN You create a VLAN by using the Create VLAN wizard, which allows you to
do the following: Configure basic VLAN properties.
■
Add ports to a VLAN.
■
Configure Spanning Tree Protocol (STP).
■
Configure STP port information.
■
Configure Internet Group Management Protocol (IGMP).
■
Configure static multicast port information.