Example 3, 1D Trunk Connection to 802.1Q VLAN Network
VLAN Operation and Network Applications
12-35
Figure 12-19
Bridge 1 Broadcasts Frames
3. Switch 2 receives the tagged Red VLAN frame on Port 2, as shown in
Figure 12-20
. The VLAN
Tag in the frame is maintained, classifying the frame as belonging to the Red VLAN. The switch
forwards the broadcast frame out all the eligible ports, Ports 3 and 4. Switch 2 simultaneously
updates its Source Address Table for FID 1 to reflect the location of User B (Port 2).
The frame forwarded out Port 3 has its VLAN Tag stripped before transmission, and it is passed
to Bridge 4 as a normal broadcast frame. The frame that is transmitted out Port 4, the 1Q Trunk,
retains its VLAN tag.
Figure 12-20
Switch 2 Forwards to 1Q Trunk
Floor 4
1
Bridge 1
Bridge 2
Red VLAN
Red VLAN
Blue VLAN
Blue VLAN
User B
2
4
3
4
2263_18
4
Floor 2
Floor 3
Bridge 3
Bridge 4
Red VLAN
Red VLAN
Blue VLAN
Blue VLAN
File Server
2
1
2
3
2263_19