Implementing Bpdu Tunneling - HP A5830 Configuration Manual

 LLDP
 PAGP
 PVST
 STP
 UDLD
 VTP

Implementing BPDU tunneling

NOTE:

This document uses the term

STP calculates the topology of a network by transmitting BPDUs among devices in the network. For more
information, see "Spanning tree configuration."
The BPDU tunneling implementations for different protocols are all similar. This section uses the STP as an
example to describe how to implement BPDU tunneling.
To avoid loops in your network, enable STP on your devices. When the topology changes are at one
side of the customer network, devices at that side of the customer network send BPDUs to devices on the
other side of the customer network to make sure consistent spanning tree calculation in the entire customer
network. However, because BPDUs are Layer 2 multicast frames, all STP-enabled devices, both in the
customer network and in the service provider network, can receive and process these BPDUs. In this case,
neither the service provider network nor the customer network can correctly calculate its independent
spanning tree.
BPDU tunneling allows each network to calculate an independent spanning tree with STP.
BPDU tunneling delivers the following benefits:
BPDUs can be transparently transmitted. BPDUs of one customer network can be broadcast in a

specific VLAN across the service provider network, allowing that customer's geographically
dispersed networks to implement consistent spanning tree calculation across the service provider
network.
BPDUs of different customer networks can be confined within different VLANs for transmission on the

service provider network. This enables each customer network to perform independent spanning tree
calculation.
Figure 28 Network diagram for BPDU tunneling implementation
CE 1
User A network 1
STP
in a broad sense. It includes STP, RSTP, and MSTP.
PE 1
ISP network
BPDU tunnel
PE 2
CE 2
User A network 2
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