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IEEE 802.1Q (tag) ‐based VLANs enable the Ethernet functionality to propagate tagged packets across the bridges and provides a
uniform way for creating VLAN within a network then span across the network. For egress packet, you can choose to tag it or not
with the associated VLAN ID of this port. For ingress packet, you can forward this packet to a specific port as long as it is also in the
same VLAN group.
The 802.1Q VLAN works by using a tag added to the Ethernet packets. The tag contains a VLAN Identifier (VID) which belongs to a
specific VLAN group. And ports can belong to more than one VLAN.
The difference between a port‐based VLAN and a tag‐based VLAN is that the tag‐based VLAN truly divided the network into several
logically connected LANs. Packets rambling around the switches can be forwarded more intelligently. In the figure shown below, by
identifying the tag, broadcast packets coming from computer A in VLAN1 at sw1 can be forwarded directly to VLAN1. However, the
switch could not be so smart in the port‐based VLAN mechanism. Broadcast packets will also be forwarded to port 4 of sw2. It means
the port‐based VLAN can not operate a logical VLAN group among switches.
The TEG‐S2620Isupports both port‐based VLAN and tag‐based (802.1Q) VLAN modes. The default configuration is tag‐based (802.1Q)
VLAN. In the 802.1Q VLAN, initially, all ports on the switch belong to default VLAN, VID is 1.
NOTE: You cannot delete the default VLAN group in 802.1Q VLAN mode.
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