Huawei AR1200 Series Configuration Guide

Run the display bgp routing-table label command on the ASBR. If information about the label
of the IPv4 route is displayed, the configuration is successful.
Run the display ip routing-table vpn-instance command on the PE. If the VPN routes to related
CEs are displayed, the configuration is successful.
3.9 Configuring Inter-AS VPN Option C (Solution 2)
After LDP LSPs are established for the labeled BGP routes of the public network, EBGP
connections in multi-hop mode are established between PEs of different ASs to exchange VPNv4
routes.
3.9.1 Establishing the Configuration Task
Before configuring inter-AS VPN OptionC, familiarize yourself with the applicable
environment, complete the pre-configuration tasks, and obtain the required data. This can help
you complete the configuration task quickly and accurately.
Applicable Environment
If the MPLS backbone network bearing VPN routes spans multiple ASs, the inter-AS VPN is
required.
If each AS needs to exchange a large number of VPN routes, inter-AS VPN-Option C is a good
choice to prevent the ASBR from becoming a bottleneck that impedes network expansion. Two
solutions can be adopted to realize inter-AS VPN-Option C:
l Solution 1: After learning the labeled BGP routes of the public network in the remote AS
from the remote ASBR, the local ASBR allocates labels for these routes, and advertises
these routes to the IBGP peer that supports the label switching capability. In this manner,
a complete LSP is set up.
l Solution 2: The IBGP peer relationship between the PE and the ASBR is not needed. In
this solution, an ASBR learns the labeled public BGP routes of the remote AS from the
peer ASBR. Then these labeled public BGP routes are imported to IGP to trigger the
establishment of an LDP LSP. In this manner, a complete LDP LSP can be established
between the two PEs.
If an ASBR is ready to access a large number of PEs, Solution 2 is recommended because of the
easy configuration.
Pre-configuration Tasks
Before configuring inter-AS VPN-Option C, complete the following tasks:
l Configuring IGP for the MPLS backbone network of each AS to ensure IP connectivity of
the backbone network within an AS
l Configuring the basic MPLS functions and MPLS LDP for the MPLS backbone network
of each AS
l Configuring VPN instances on PEs that access CEs, and associating VPN instances with
PE interfaces that connect CEs
l Configuring IP addresses on CE interfaces that access PEs
Huawei AR1200 Series Enterprise Routers
Configuration Guide - VPN 3 BGP MPLS IP VPN Configuration
Issue 01 (2012-04-20) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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Huawei AR1200 Series Specifications

General

Brand	Huawei
Model	AR1200 Series
Category	Network Router
Language	English