Operation Manual – VLAN-VPN
H3C S3100 Series Ethernet Switches
Chapter 4 BPDU Tunnel Configuration
4-1
Chapter 4 BPDU Tunnel Configuration
Note:
This chapter is only applicable to S3100-EI series switches.
When configuring BPDU tunnel, go to these sections for information you are interested
in:
z
BPDU Tunnel Overview
z
BPDU Tunnel Configuration
z
Displaying and Maintaining BPDU Tunnel Configuration
z
BPDU Tunnel Configuration Example
4.1 BPDU Tunnel Overview
4.1.1 Introduction to the BPDU Tunnel Feature
Normally, Layer 2 protocols are needed in a LAN for network topology maintenance
and management. For example, spanning tree protocol (STP) is used for maintaining
spanning trees and preventing loops. Huawei group management protocol (HGMP) is
used for managing network topology and devices in a network.
When multiple branch networks of an organization are connected together through a
public network, you can combine the corresponding network nodes into one so as to
maintain the branch networks as a whole. This requires the packets of some of the
user’s Layer 2 protocol packets be transmitted across the provider’s network without
getting involved in the computation of the public network.
The BPDU Tunnel feature is designed to address the above requirements. It enables
some Layer 2 protocol packets of private networks to be transmitted along tunnels
established in the public network.
4.1.2 BPDU Tunnel Fundamental
I. Layer 2 protocol packet identification
Different from the processing of data packets, a Layer 2 protocol packet is classified
first when it reaches a network device. A Layer 2 protocol packet conforming to IEEE
standards carries a special destination MAC address (for example, the destination
MAC address of an STP protocol packet is 0180-c200-0000) and contains a type field.
Some proprietary protocols adopt the same packet structure, where a private MAC