Port-Based Virtual LANs (VLANs) and GVRP

Port-Based Virtual LANs (Static VLANs)

 

Blue

 

Blue

White

White

 

Server

VLAN

Server

VLAN

Red

5

6

Red VLAN: Untagged

4

3

VLAN

4

 

Green VLAN: Tagged

 

 

 

Switch

Switch

 

7

5

 

3

"X"

 

 

 

"Y"

Red

 

 

 

 

 

2

1

 

 

1

2

Server

 

 

 

 

 

 

 

 

 

Green

Green

Red

 

Green

 

Server

VLAN

VLAN

VLAN

 

Ports 1-6: Untagged

Ports 1-4: Untagged

 

Port 7: Red VLAN Untagged

Port 5: Red VLAN Untagged

 

Green VLAN Tagged

Green VLAN Tagged

Figure 11-17. Example of Tagged and Untagged VLAN Port Assignments

In switch X:

VLANs assigned to ports X1 - X6 can all be untagged because there is only one VLAN assignment per port. Red VLAN traffic will go out only the Red ports; Green VLAN traffic will go out only the Green ports, and so on. Devices connected to these ports do not have to be 802.1Q- compliant.

However, because both the Red VLAN and the Green VLAN are assigned to port X7, at least one of the VLANs must be tagged for this port.

In switch Y:

VLANs assigned to ports Y1 - Y4 can all be untagged because there is only one VLAN assignment per port. Devices connected to these ports do not have to be 802.1Q-compliant.

Because both the Red VLAN and the Green VLAN are assigned to port Y5, at least one of the VLANs must be tagged for this port.

In both switches: The ports on the link between the two switches must be configured the same. As shown in figure 11-17(above), the Red VLAN must be untagged on port X7 and Y5 and the Green VLAN must be tagged on port X7 and Y5, or vice-versa.

11-23