Allied Telesis AT-S63 - Manual (Page 614)

Chapter 25: Multiple VLANs
614 Section V: VLANs
This highly segmented configuration is useful in situations where traffic
generated by each end node or network segment connected to a port on
the switch needs to be kept separate from all other network traffic, while
still allowing access to an uplink to a WAN. Unicast traffic received by the
uplink port is effectively directed to the appropriate port and end node and
is not directed to any other port on the switch.
The 802.1Q Multiple VLAN configuration is appropriate when the device
connected to the uplink port is IEEE 802.1Q compatible, meaning that it
can handle tagged packets.
When you select the 802.1Q-compliant VLAN mode, you are asked to
specify the uplink VLAN port. You can specify only one uplink port. The
switch automatically configures the ports into the separate VLANs.
Note
The uplink VLAN is the management VLAN. Any remote
management of the switch must be made through the uplink VLAN.
Non-802.1Q
Compliant
Multiple VLAN
Mode
Unlike the 802.1Q-compliant VLAN mode, which isolates port traffic by
placing each port in a separate VLAN, this mode forms one VLAN with a
VID of 1 that encompasses all ports. To establish traffic isolation, it uses
port mapping. The result, however, is the same. Ports are permitted to
forward traffic only to the designated uplink port and to no other port, even
when they receive a broadcast packet.
Another difference with this mode is that the uplink port is untagged.
Consequently, you would use this mode when the device connected to the
uplink port is not IEEE 802.1Q compatible, meaning that the device cannot
handle tagged packets.
Client_VLAN_19 19 19 22
Client_VLAN_20 20 20 22
Client_VLAN_21 21 21 22
Uplink_VLAN 22 22
Client_VLAN_23 23 23 22
Client_VLAN_24 24 24 22
Table 21. 802.1Q-Compliant Multiple VLAN Example (Continued)
VLAN Name VID Untagged Port Tagged Port