Link Types of ports
When creating the 802.1Q VLAN, you should set the link type for the port according to its
connected device. The link types of port including the following three types:
1.
ACCESS:
The ACCESS port can be added in a single VLAN, and the egress rule of the
port is UNTAG. The PVID is same as the current VLAN ID. If the ACCESS port is added to
another VLAN, it will be removed from the current VLAN automatically.
2.
TRUNK:
The TRUNK port can be added in multiple VLANs. The egress rule of the port is
UNTAG if the arriving packet’s VLAN tag is the same as the port’s PVID, otherwise the
egress rule is TAG. The TRUNK port is generally used to connect the cascaded network
devices for it can receive and forward the packets of multiple VLANs.
3.
GENERAL:
The GENERAL port can be added in multiple VLANs and set various egress
rules according to the different VLANs. The default egress rule is UNTAG. The PVID can
be set as the VID number of any valid VLAN.
PVID
PVID (Port VLAN ID) is the default VID of the port. When the switch receives an
un-VLAN-tagged packet, it will add a VLAN tag to the packet according to the PVID of its
received port and forward the packets.
When creating VLANs, the PVID of each port, indicating the default VLAN to which the port
belongs, is an important parameter with the following two purposes:
1.
When the switch receives an un-VLAN-tagged packet, it will add a VLAN tag to the
packet according to the PVID of its received port
2.
PVID determines the default broadcast domain of the port, i.e. when the port receives
UL packets or broadcast packets, the port will broadcast the packets in its default
VLAN.
Different packets, tagged or untagged, will be processed in different ways, after being received
by ports of different link types, which is illustrated in the following table.
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