D-Link DGS-3000 Series Reference Manual page 83

0
EtherType=0x8100
MAC Length/Type
User Prlorlty
The EtherType and VLAN ID are inserted after the MAC source address, but before the original EtherType/Length or
Logical Link Control. Because the packet is now a bit longer than it was originally, the Cyclic Redundancy Check
(CRC) must be recalculated.
Dst. MAC
6
Dst. MAC Src. MAC
6
16
Port VLAN ID
DGS-3000 Series Gigabit Ethernet Switch Web UI Reference Guide
1
Destination Address (6 octets)
Source Address (6 octets)
Cyclic Redundancy Check (4 octets)
CFI
Figure 4-2 IEEE 802.1Q Tag
Src. MAC
6
6 4
Tag Control Information (TCI)
3
Figure 4-3 Adding an IEEE 802.1Q Tag
2
Tag Control Information
Beginning of Data
VLAN ID (VID) (12 bits)
2 Up to 1500
2 Up to 1500
1
74
3
Original Ethernet Packet
bytes
4
New Tagged Packet
bytes
4
bites
12
4