37
TPID: The 16-bit TPID field with a value of 0x8100 indicates that the frame is VLAN-tagged.
Priority: The 3-bit priority field indicates the 802.1P priority of the frame (0-7).
CFI: CFI is a 1-bit field, indicating whether the MAC address is encapsulated in the standard format in different
transmission media. A value of 0 indicates that MAC addresses are encapsulated in the standard format. A value of
1 indicates that MAC addresses are encapsulated in a non-standard format. For Ethernet switches, it is advisable to
set this value to 0.
VID: The 12-bit VLAN ID field identifies the VLAN that the frame belongs to. The VLAN ID range is 0 to 4095.
Because 0 and 4095 are reserved, a VLAN ID actually ranges from 1 to 4094.
802.1Q VLAN Port link type:
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:
Access
: An access port belongs to only one VLAN. It is usually used to connect a PC.
Trunk
: A trunk port can carry multiple VLANs to receive and send traffic for them. Usually, ports that connect
switches are configured as trunk ports.
Hybrid
: Like a trunk port, a hybrid port can carry multiple VLANs to receive and send traffic for them. A port
connected to a network device or user terminal can be configured as a hybrid port.
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:
Port Type
Receiving
Tagged Packets
Receiving
Untagged
Packets
Forwarding Packets
Access
The packet will
be forwarded to
other ports in the
corresponding
VLAN according
to the VID in the
Tag
The packet will
be forwarded to
other ports in the
corresponding
VLAN
according to
PVID on this
port
The packet will be forwarded after removing its
VLAN tag.
Trunk
If the VID of packet is the same as the PVID of the
port, the packet will be forwarded after removing its
VLAN tag; If the VID of packet is not the same as
the PVID of the port, the packet will be directly
forwarded.
Hybrid
If the VID value of the packet belongs to Tagged
VLAN, the packet will be forwarded with Tag;
If the VID value of the packet belongs to Untagged
VLAN, the packet will be forwarded after removing
its VLAN tag.
Содержание G3224P
Страница 1: ......
