3Com WX2200 3CRWX220095A Switch User Manual


 
90 CHAPTER 5: CONFIGURING AND MANAGING PORTS AND VLANS
Because the default VLAN (VLAN 1) might not be in the same subnet on
each 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 switch 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 port 6 is not
switched and needs to be routed by an external router.
802.1Q Tagging
The tagging capabilities of the WX switch are very 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. MSS does not require the VLAN number and tag value
to be the same, but some other 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.
MSS automatically assigns tag values to Distributed MAPs. Each of these
tag values represents a unique combination of radio, encryption type, and
VLAN. These tag values do not necessarily correspond to tag values you
configure on the VLAN ports through which the Distributed MAP is
connected to the WX.
Tunnel Affinity
WX switches configured as a Mobility Domain allow users to roam
seamlessly across MAPs and even across WX switches. Although a switch
that is not a member of a user’s VLAN cannot directly forward traffic for
the user, the switch can tunnel the traffic to another WX switch that is a
member of the user’s VLAN.