Nortel Networks 2000 Manual De Usuario

Chapter 2 Network configuration 111

Using the Business Policy Switch 2000 Version 1.2

 

As shown in 

, the tagged packet remains unchanged as it leaves the 

switch through port 5, which is configured as a tagged member of VLAN 2. 
However, the tagged packet is stripped (untagged) as it leaves the switch through 
port 7, which is configured as an untagged member of VLAN 2.

Figure 24   802.1Q tagging (after 802.1Q tag assignment)

You can use VLANs to segment a network within a switch. When you connect 
multiple switches, it is possible to connect users of one VLAN with users of that 
same VLAN in another switch. However, the configuration guidelines depend on 
whether both switches support 802.1Q tagging.

With 802.1Q tagging enabled on a port for a VLAN, all frames leaving the port for 
that VLAN are marked as belonging to that specific VLAN. You can assign 
specific switch ports as members of one or more VLANs that span multiple 
switches, without interfering with the Spanning Tree Protocol.

Refer to Chapter 1 for additional guidelines on configuring VLANs and spanning 
tree groups.

BS45014A

Port 6

Port 7

Port 8

Port 1

Po

rt

 4

Po

rt

 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

DA

SA

Data

CRC*

(*Recalculated)

Outgoing
untagged packet
changed
(tag removed)

DA

SA

Data

CRC

Tag

VID = 2

Priority

16 bits

3 bits

1 bit

12 bits

8100

CFI