Enterasys Networks 802.1Q - Manual (Page 66)

Example 2, VLANs Across Multiple Switches
4-6 Examples
2. A Port VLAN ID is assigned to each port (1 and 3) as follows using the Port Assignment screen:
• Port 1, VLAN ID: 223 for the Blue VLAN
• Port 3, VLAN ID: 222 for the Red VLAN
These settings change the configuration of the switch, so that Port 1 is part of Blue VLAN, Port
3 is part of Red VLAN, and both are set as frame type of untagged.
3. Port 2 is configured as a 1Q Trunk port as follows using the Port Assignment Configuration
screen:
• Port 2, Port Mode: 1Q Trunk
Port 2 is set as an 802.1Q Trunk port, which makes its Port VLAN List contain all VLANs and
sets all frames forwarded out this port as tagged frames. This completes the transmission path
between Switch 4 and Switch 2.
4.2.2 Frame Handling
The following describes how, when User A attempts to log on to the File Server on Bridge 4, the
frames from User A are classified on Switch 4 and traverse the network. In this example, the MAC
address of User A is “Y” and the MAC address for the File Server is “Z”. The following
description includes illustrations to help understand how the frames flow through the network.
1. User A sends a frame with a Broadcast Destination Address in an attempt to locate the File
Server. The frame is received on User A’s port of Bridge 1 and, because the frame is a broadcast
frame, it is transmitted out all ports of Bridge 1 as shown in
Figure 4-4 .
Figure 4-4 Bridge 1 Broadcasts Frames
Floor 4
2263_14
1 3
2
Bridge 1 Bridge 2
Redco Blue Industries
Red VLAN Red VLAN Blue VLAN Blue VLAN
User A
4
4