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”.
Note 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
Port
Tagging Scheme
1 Untagged 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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