Huawei AR1200 Series Configuration Guide

3.6 Configuring Inter-AS VPN Option A
In inter-AS VPN OptionA, an ASBR takes the peer ASBR as its CE and advertises VPNv4 routes
to the peer ASBR through EBGP.
3.6.1 Establishing the Configuration Task
Before configuring inter-AS VPN OptionA, 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 the VPN routes is across multiple ASs, configure the
Inter-AS VPNs.
The Inter-AS VPN Option A is convenient to implement and is suitable when the amount of the
VPNs and the VPN routes on the PE is small.
In VPN-Option A, the Autonomous System Boundary Routers (ASBRs) must support the VPN
instances and can manage VPN routes. In addition, the ASBRs must reserve special interfaces
including sub-interfaces and physical interfaces for each inter-AS VPN. Option A, therefore,
requires high performance of the ASBRs. No inter-AS configuration is needed on the ASBRs.
Pre-configuration Tasks
Before configuring inter-AS VPN Option A, complete the following tasks:
l Configuring IGP for MPLS backbone networks in each AS to keep IP connectivity of the
backbones in one AS
l Enabling MPLS and MPLS LDP on the PE and the ASBR
l Setting up the tunnel (LSP or GRE) between the PE and the ASBR in the same AS
l Configuring the IP address of the CE interface through which the CE accesses the PE
Data Preparation
To configure inter-AS VPN Option A, you need the following data:
No.
Data
1 Data for configuring a VPN instance on the PE and ASBR:
l Name of the VPN instance
l (Optional) Description of the VPN instance
l RD, VPN target attribute of the VPN instance IPv4 address families
l (Optional) Routing policy
l (Optional) Tunnel policy
l (Optional) Maximum number of routes permitted in the VPN instance IPv4
address families
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