Static Virtual LANs (VLANs)

Port-Based Virtual LANs (Static VLANs)

The VLANs assigned to ports X3, X4, Y2, Y3, and Y4 can all be untagged because there is only one VLAN assigned per port. Port X1 has multiple VLANs assigned, which means that one VLAN assigned to this port can be untagged and any others must be tagged. The same applies to ports X2, Y1, and Y5.

Switch X

 

 

Switch Y

 

Port

Red VLAN

Green VLAN

 

Port

Red VLAN

Green VLAN

 

 

 

 

 

 

 

X1

Untagged

Tagged

 

Y1

Untagged

Tagged

X2

Untagged

Tagged

 

Y2

No*

Untagged

X3

No*

Untagged

 

Y3

No*

Untagged

X4

Untagged

No*

 

Y4

Untagged

No*

 

 

 

 

Y5

Untagged

Tagged

 

 

 

 

 

 

 

*”No” means the port is not a member of that VLAN. For example, port X3 is not a member of the Red VLAN and does not carry Red VLAN traffic. Also, if GVRP were enabled, “Auto” would appear instead of “No”.

N o t e

 

VLAN configurations on ports connected by the same link must match.

 

 

Because ports X2 and Y5 are opposite ends of the same point-to-point connec­

 

 

tion, both ports must have the same VLAN configuration; that is, both ports

 

 

configure the Red VLAN as “Untagged” and the Green VLAN as “Tagged”.

 

 

To summarize:

 

 

 

 

 

 

 

VLANs Per Tagging Scheme

 

 

Port

 

 

 

1Untagged or Tagged. If the device connected to the port is 802.1Q-compliant, then the recommended choice is “Tagged”.

2 or More

1 VLAN Untagged; all others Tagged

 

or

 

All VLANs Tagged

A given VLAN must have the same VID on any 802.1Q-compliant device in which the VLAN is configured.

The ports connecting two 802.1Q devices should have identical VLAN configurations, as shown for ports X2 and Y5, above.

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