User's Manual

Table Of Contents
Configuration Guide of XGS-5240-Series
138
service provider network. As shown in Figure, User A has two devices (CE 1 and CE 2) and
both devices belong to the same VLAN. User’s network is divided into network 1 and network
2, which are connected by the service provider network. When Layer 2 protocol packets
cannot implement the passthrough across the service provider network, the users network
cannot process independent Layer 2 protocol calculation (for example, spanning tree
calculation), so they affect each other.
Fig 8-2 BPDU Tunnel application environment
With BPDU Tunnel, Layer 2 protocol packets from user’s networks can be passed through
over the service provider network in the following work flow:
1. After receiving a Layer 2 protocol packet from network 1 of user A, PE 1 in the service
provider network encapsulates the packet, replaces its destination MAC address with a
specific multicast MAC address, and then forwards the packet in the service provider network.
2. The encapsulated Layer 2 protocol packet (called BPDU Tunnel packet) is forwarded 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 network 2 of
user A.
bpdu-tunnel-protocol configuration of edge switches PE1 and PE2 in the following:
PE1 Configuration:
PE1(config-if-ethernet1/1)# bpdu-tunnel-protocol stp
PE1(config-if-ethernet1/1)# bpdu-tunnel-protocol lacp
PE1(config-if-ethernet1/1)# bpdu-tunnel-protocol dot1x
PE2(config-if-ethernet1/1)# bpdu-tunnel-protocol user-defined-protocol uldp
PE2 Configuration:
PE2(config-if-ethernet1/1)# bpdu-tunnel-protocol stp
PE2(config-if-ethernet1/1)# bpdu-tunnel-protocol gvrp
PE2(config-if-ethernet1/1)# bpdu-tunnel-protocol dot1x
PE2(config-if-ethernet1/1)# bpdu-tunnel-protocol user-defined-protocol uldp
bpdu-tunnel