Cabletron Systems 802.1Q - Manual (Page 76)

Chapter 4: Examples
4-10 802.1Q VLAN User’s Guide
Figure 4-6 Transmitting to Bridge 4
4. The File Server responds with a unicast frame to User A. All switches
between the File Server and User A have an entry in their respective
Source Address Tables identifying which port to use for forwarding
the frame to User A, MAC address “Y” in FID 3. All switches update
their Source Address Tables for the File Server’s MAC address “Z” as
the frame is forwarded through the switch fabric to User A. The
802.1D switches update their Source Address Tables based on the
source MAC address and receive port and the 802.1Q switches update
their databases based on the source MAC address, VLAN, and receive
port.
5. The frame from the File Server is received on Switch 2, and forwarded
to Switch 1 as a tagged frame classified as belonging to the Red
VLAN. Switch 1 removes the tag and forwards the frame to Bridge 1,
which in turn forwards the frame out of the port attached to User A.
All subsequent frames between User A and the File Server are
forwarded through the switch fabric in the same manner.
4.3 EXAMPLE 3, 1D TRUNK CONNECTION TO 802.1Q
VLAN NETWORK
This example illustrates the use of a 1D Trunk to connect a device to a
network of 802.1Q VLAN switches.
In this example, a merger has taken place between the companies in the
previous example, Redco and Blue Industries. The two companies have
become divisions within a single corporation, Green Incorporated.
Floor 2
2263_16
Floor 3
1 3
2
Bridge 3 Bridge 4
Redco Blue Industries
Red VLAN Red VLAN Blue VLAN Blue VLAN
File Server
2