14-26
Port-Based Virtual LANs (VLANs) and GVRP
Port-Based Virtual LANs (Static VLANs)
Port-Based Virtual LANs
(VLANs) and GVRP
Figure 14-19. Example of Networked 802.1Q-Compliant Devices with Multiple
VLANs on Some Ports
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.
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 c onnec-
tion, both ports must have the same VLAN configuration; that is, both ports
configure the Red VLAN as “Untagged” and the Green VLA N as “Tagged”.
RedVLAN: Untagged
RedVLAN: Untagged Red VLAN: Untagged
GreenVLAN: Tagged
GreenVLAN: Tagged GreenVLAN: Tagged
GreenVLAN only
Server
S1
Server
S2
Server
S3
Green
VLAN
Green
VLAN
Red
VLAN
Red
VLAN
Switch
"X"
X1
X2
X3
X4
Switch
"Y"
Y1
Y4
Y2Y5
Y3
Switch X Switch Y
Port Red VLAN Green VLAN Port Red V LAN Green VLAN
X1 Untagged Tagged Y1 Unt agged 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 R ed VLAN traffic. Also, if GVRP
were enabled, “Auto” would appear instead of “No”.