FGSW-2620VM User’s Manual
Every physical port on a switch has a PVID. 802.1Q ports are also assigned a PVID, for use within the switch. If no
VLAN are defined on the switch, all ports are then assigned to a default VLAN with a PVID equal to 1. Untagged packets
are assigned the PVID of the port on which they were received. Forwarding decisions are based upon this PVID, in so
far as VLAN are concerned. Tagged packets are forwarded according to the VID contained within the tag. Tagged
packets are also assigned a PVID, but the PVID is not used to make packet forwarding decisions, the VID is.
Tag-aware switches must keep a table to relate PVID within the switch to VID on the network. The switch will compare
the VID of a packet to be transmitted to the VID of the port that is to transmit the packet. If the two VID are different the
switch will drop the packet. Because of the existence of the PVID for untagged packets and the VID for tagged packets,
tag-aware and tag-unaware network devices can coexist on the same network.
A switch port can have only one PVID, but can have as many VID as the switch has memory in its VLAN table to store
them.
Because some devices on a network may be tag-unaware, a decision must be made at each port on a tag-aware device
before packets are transmitted – should the packet to be transmitted have a tag or not? If the transmitting port is
connected to a tag-unaware device, the packet should be untagged. If the transmitting port is connected to a tag-aware
device, the packet should be tagged.
Default VLANs
The Switch initially configures one VLAN, VID = 1, called
"default."
The factory default setting assigns all ports on the
Switch to the
"default"
. As new VLAN are configured in Port-based mode, their respective member ports are removed
from the "default."
VLAN and Link aggregation Groups
In order to use VLAN segmentation in conjunction with port link aggregation groups, you can first set the port link
aggregation group(s), and then you may configure VLAN settings. If you wish to change the port link aggregation
grouping with VLAN already in place, you will not need to reconfigure the VLAN settings after changing the port link
aggregation group settings. VLAN settings will automatically change in conjunction with the change of the port link
aggregation group settings
4.3.1.1 VLAN configuration
A Virtual LAN (VLAN) is a logical network grouping that limits the broadcast domain. It allows you to isolate network
traffic so only members of the VLAN receive traffic from the same VLAN members. Basically, creating a VLAN from a
switch is logically equivalent of reconnecting a group of network devices to another Layer 2 switch. However, all the
network devices are still plug into the same switch physically.
The switch supports port-based, 802.1Q (tagged-based) and protocol-base VLAN in web management page. In the
default configuration, VLAN support is “disable”.
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