Allied Telesis AT-S63 - Manual (Page 440)

Chapter 19: Port-based and Tagged VLANs
440 Section III: VLANs
This example is nearly identical to the ”Port-based Example 2” on page
434. Tagged ports have been added to simplify network implementation
and management.
One of the tagged ports is port 5 on the top switch. This port has been
made a tagged member of the three VLANs. It is connected to an IEEE
802.1Q-compliant server, meaning the server can handle frames from
multiple VLANs. Now all three VLANs can access the server without
going through a router or other interconnection device.
It is important to note that even though the server is accepting frames
from and transmitting frames to more than one VLAN, data separation
and security remain.
Two other tagged ports are used to simplify network design in the
example. They are ports 5 and 8 on the upper switch and port 7 on the
lower switch. These ports have been made tagged members of the Sales
and Engineering VLANs. They provide a connection between the
different parts of these two VLANs.
In the ”Port-based Example 2” on page 434, each VLAN needed its own
data link between the switches to connect the different parts of the
VLANs. But with tagged ports, you can use one data link to carry data
traffic from several VLANs, while still maintaining data separation and
security. The tagged frames, when received by the switch, are delivered
only to those ports that belong to the VLAN from which the tagged
frame originated.
AT-9424T/GB
Switch
(bottom) 1-4 (PVID 2) 7 114, 16, 18, 22
(PVID 3) 7 none none
Sales VLAN (VID 2) Engineering VLAN (VID 3) Production VLAN (VID 4)