Nortel BayStack 450-24T - Figure 1-25. 802.1 Q Tagging (after Port-Based Vlan Assignment); Figure 1-26. Protocol-Based Vlan Assignment

BayStack 450 10/100/1000 Series Switches
309978-D Rev 01 1-55
As shown in Figure 1-25, 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 1-25. 802.1Q Tagging (After Port-Based VLAN Assignment)
In Figure 1-26, untagged incoming packets are assigned to VLAN 3 (IP Protocol
VLAN = 3, PVID = 2). Port 5 is configured as a tagged member of VLAN 3, and
port 7 is configured as an untagged member of VLAN 3.
Figure 1-26. Protocol-Based VLAN Assignment
BS45084A
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
PVID = 2
Tagged member
of VLAN 2
Untagged member
of VLAN 2
After
DA
SA
Data
CRC
(*Recalculated)
Outgoing
untagged packet
(unchanged)
DASADataCRC* Ta g
VID = 2Priority
16 bits 3 bits 1 bit 12 bits
8100 CFI
Port 6
DASADataCRC
BS45011B
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 3
Tagged member
of VLAN 3
Before
IP Protocol VLAN = 3