Configuring Bpdu Tunneling - HP A5830 Configuration Manual

Configuring BPDU tunneling

BPDU tunneling is a Layer 2 tunneling technology. With BPDU tunneling, Layer 2 protocol packets from
geographically dispersed customer networks can be transparently transmitted across a service provider
network, using specific tunnels.
BPDU addresses problems that arise when parts of a user network are located at different sides of a
service-provider network. For example,
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). However, when a PE receives a Layer 2
protocol packet, it cannot determine whether the packet is from the user network or the service
provider network. Therefore, it must deliver the packet to the CPU for processing.
In the example, 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 27 BPDU tunneling application scenario
CE 1
User A network 1
VLAN 100
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 BPDU) is forwarded to PE 2 at the other end of
2.
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.
HP devices support BPDU tunneling for the following protocols:
CDP

DLDP

Ethernet Operation, Administration and Maintenance (EOAM)

GVRP

HGMP

LACP

Figure 27
PE 1
ISP network
94
shows User A's network 1 and network 2 connected by
PE 2
CE 2
User A network 2
VLAN 100