Proscend 6200-2W, Руководство пользователя

Страница: 44 / 93

41
according to the PVID (port VLAN) port definition. Typically, most switches today have all ports are set to a default
PVID of 1. When a tagged frame arrives at a switch port the tag is respected.
A VID defines the member of a port group. A packet can only travel inside a member port when the member port is
part of a VID port group. Different VID groups aren’t visible to one another
VID: (Virtual LAN ID) It is an definite number of ID which number is from 1 to 4094.
PVID: (Port VID) It is an untagged member from 1 to 4094 of default VLAN.
Link Type: Access means the port can receive or send untagged packets.
Trunk means that the prot can receive or send tagged packets.
TCI (Tag Control Information field) including user priority, Canonical format indicator(CFI) and VLAN ID.
TPID(Tag Protocol Identifier) defined value of 8100 in hex. When a frame has the EtherType equal to 8100H, this frame
carries the tag IEEE 802.1Q / 802.1P.
Priority field defines user priority, giving eight (2
3
= 8) priority levels. IEEE 802.1P defines the operation for these 3
user priority bits.(Refer to following table)
CFI(Canonical Format Indicator) is always set to zero for Ethernet switches. CFI is used for compatibility reason
between Ethernet type network and Token Ring type network. If a frame received at an Ethernet port has a CFI set to
1, then that frame should not be forwarded as it is to an untagged port.
VID (VLAN ID) is the identification of the VLAN, which is basically used by the standard 802.1Q. It has 12 bits and allow
the identification of 4096 (2
12
) VLANs. Of the 4096 possible VIDs, a VID of 0 is used to identify priority frames and
value 4095 (FFF) is reserved, so the maximum possible VLAN configurations are 4,094.
The VPN Router initially default configures one VLAN, VID=1.
A port such as LAN1 to 4, DSL or sniffing can have only one PVID, but can have as many VID as the VPN Router has
memory in its VLAN table to store them.