Configuring Bpdu Tunneling (Available Only On The Hpe 3100 V2 Ei); Overview; Background - HP 3100 Series Configuration Manual

Configuring BPDU tunneling (available
only on the HPE 3100 v2 EI)

Overview

As a Layer 2 tunneling technology, BPDU tunneling enables Layer 2 protocol packets from
geographically dispersed customer networks to be transparently transmitted over specific tunnels
across a service provider network.

Background

Dedicated lines are used in a service provider network to build user-specific Layer 2 networks. As a
result, a user network consists of parts located at different sides of the service provider network. As
shown in Figure
User A's network is divided into network 1 and network 2, which are connected by the service
provider network. When a Layer 2 protocol (for example, STP) runs on both network 1 and network 2,
the Layer 2 protocol packets must be transmitted over the service provider network to implement
Layer 2 protocol calculation (for example, spanning tree calculation). When receiving a Layer 2
protocol packet, the PEs cannot determine whether the packet is from the user network or the
service provider network, and must deliver the packet to the CPU for processing. In this case, the
Layer 2 protocol calculation in User A's network is mixed with that in the service provider network,
and the user network cannot implement independent Layer 2 protocol calculation.
Figure 28 BPDU tunneling application scenario
BPDU tunneling addresses this problem. With BPDU tunneling, Layer 2 protocol packets from
customer networks can be transparently transmitted over the service provider network in the
following workflow:
After receiving a Layer 2 protocol packet from CE 1, PE 1 encapsulates the packet, replaces its
1.
destination MAC address with a specific multicast MAC address, and forwards the packet to the
service provider network.
The encapsulated Layer 2 protocol packet (called bridge protocol data unit, BPDU) is forwarded
2.
to PE 2 at the other end of the service provider network, which de-encapsulates the packet,
restores the original destination MAC address of the packet, and then sends the packet to CE 2.
HPE 3100 v2 EI devices support BPDU tunneling for the following protocols:
•
Cisco Discovery Protocol (CDP)
•
HW Group Management Protocol (HGMP)
•
Link Aggregation Control Protocol (LACP)
28, the devices for User A are CE 1 and CE 2, both of which belong to VLAN 100.
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