Specifications

32 | Appendix B: IEEE 802.1Q Virtual Local Area Network (VLAN)
Smart Switch Software Manual
IEEE 802.1Q VLANs
Packets received by the switch will be treated in the following way:
• When an untagged packet enters a port, it will be automatically tagged with the port’s
default VLAN ID tag number. Each port has a default VLAN ID setting that is user
configurable (the default setting is 1). The default VLAN ID setting for each port can be
changed in PVID Setting page.
• When a tagged packet enters a port, the tag for that packet will be unaffected by the
default VLAN ID Setting.
• The packet will now proceed to the VLAN specified by its VLAN ID tag number.
• If the port in which the packet entered does not have membership with the VLAN
specified by the VLAN ID tag, the packet will be dropped.
• If the port has membership to the VLAN specified by the packet’s VLAN ID, the packet will
be able to be sent to other ports with the same VLAN ID membership.
• Packets leaving the switch will be either tagged or untagged depending on the setting for
that port’s VLAN membership properties. A ‘U’ for a given port means that packets
leaving the switch from that port will be Untagged. Inversely, a ‘T’ for a given port means
that packets leaving the switch from that port will be tagged with the respective VLAN ID
in which it participated in.
The example given in this section will step through a more elaborate setup illustrating all
possible scenarios for a comprehensive understanding of tagged VLANs.
Example
This example demonstrates several scenarios of VLAN use and how the switch will handle
Tagged and Untagged traffic.
1. Setup the following VLANs: VLAN 10, 20.
2. Configure the VLAN membership. Be sure to set all of them as follows.
• Setting up first VLAN group, VLAN ID = 10:
• Setting up second VLAN group, VLAN ID = 20:
3. Modify PVID Setting to apply previous two VLAN groups: Modify Default VLAN group (VLAN
ID = 1) to apply two new VLAN groups:
The specific ports above have the following Port VLAN ID settings:
• Default VLAN: Port 7 – Port 26 (all U), VID = 1
• VLAN 1: Port 1 (U), Port 2 (U), Port 3 (T), VID = 10
• VLAN 2: Port 4 (U), Port 5 (T), Port 6 (U), VID = 20.
4. The following scenarios will produce results as described below:
a. If an untagged packet enters Port 1, the switch will tag it with a VLAN tag value 10.
The packet will have access to Port 2 and Port 3. The outgoing packet will be stripped
away its tag becoming an untagged packet as it leaves Port 2. For Port 3, the
outgoing packet will leave as a tagged packet with a VLAN tag value 10.