User`s guide

Chapter 4: Examples
4-8 DIGITAL MultiSwitch 700 Port Based VLAN User’s Guide
Figure 4-4 Bridge 1 Broadcasts Frames
2. Switch 4 receives the frame from Bridge 1 and immediately classifies
it as belonging to the Red VLAN. After the frame is classified,
Switch 4 checks the Destination Address and, upon discovering that it
is a Broadcast Destination Address, forwards the frame out all ports in
the Red VLAN Forwarding List. In this example, it is only port 4.
Switch 4 updates its Source Address Table if it didn’t already have a
dynamic entry for MAC address “Y” and VLAN “Red”. Because
Switch 4 received the frame on port 1 it does not forward the packet
out that port, but does forward the frame to port 4.
The frame is transmitted to Switch 2 with a VLAN Tag Header
inserted in the frame. The VLAN Tag Header indicates that the frame
is classified as belonging to the Red VLAN. Figure 4-5 shows the path
taken to this point to reach Switch 2.
The tag is inserted because Switch 4, port 4 is designated as an 802.1Q
Trunk port. In this case, the Port Mode setting for port 4 is 802.1Q
Trunk and the VLAN Frame format for that VLAN is tagged.
Floor 4
2263n14
1
3
2
Bridge 1
Bridge 2
Redco Blue Industries
Red VLAN
Blue VLAN
User A
4
4