RackSwitch G8000 Application Guide
Chapter 3: VLANs
53BMD00041, November 2008
Figure 3-2 through Figure 3-5 illustrate generic examples of VLAN tagging. In Figure 3-2,
untagged incoming packets are assigned directly to VLAN 2 (PVID = 2). Port 5 is configured
as a tagged member of VLAN 2, and port 7 is configured as an untagged member of VLAN 2.
NOTE – The port assignments in the following figures are not meant to match the G8000.
Figure 3-2 Port-based VLAN assignment
As shown in Figure 3-3, the untagged packet is marked (tagged) as it leaves the switch through
port 5, which is configured as a tagged member of VLAN 2. The untagged packet remains
unchanged as it leaves the switch through port 7, which is configured as an untagged member
of VLAN 2.
Figure 3-3 802.1Q tagging (after port-based VLAN assignment)
Port 6
DASADataCRC
BS45011A
Port 7 Port 8
Port 1
Port 4
Port 5
Port 2 Port 3
802.1Q Switch
PVID = 2
Untagged packet
Untagged member
of VLAN 2
Tagged member
of VLAN 2
B
e
f
o
r
e
BS45012
Port 6 Port 7 Port 8
Port 1
Port 4
Port 5
Port 2 Port 3
802.1Q Switch
Key
Priority
CFI
VID
- User_priority
- Canonical format indicator
- VLAN identifier
VID = 2
of VLAN 2
Untagged memeber
of VLAN 2
After
DA
SA
Data
CRC
(*Recalculated)
Outgoing
untagged packet
(unchanged)
DASADataCRC* Tag
VID = 2Priority
16 bits 3 bits 1 bits 12 bits
8100 CFI
