Browse Prior Art Database

BGP/MPLS VPNs (RFC2547)

IP.com Disclosure Number: IPCOM000003133D
Original Publication Date: 1999-Mar-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 21 page(s) / 59K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

E. Rosen: AUTHOR [+2]

Abstract

This document describes a method by which a Service Provider with an IP backbone may provide VPNs (Virtual Private Networks) for its customers. MPLS (Multiprotocol Label Switching) is used for forwarding packets over the backbone, and BGP (Border Gateway Protocol) is used for distributing routes over the backbone. The primary goal of this method is to support the outsourcing of IP backbone services for enterprise networks. It does so in a manner which is simple for the enterprise, while still scalable and flexible for the Service Provider, and while allowing the Service Provider to add value. These techniques can also be used to provide a VPN which itself provides IP service to customers.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 5% of the total text.

Network Working Group E. Rosen

Request for Comments: 2547 Y. Rekhter

Category: Informational Cisco Systems, Inc.

March 1999

BGP/MPLS VPNs

Status of this Memo

This memo provides information for the Internet community. It does

not specify an Internet standard of any kind. Distribution of this

memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (1999). All Rights Reserved.

Abstract

This document describes a method by which a Service Provider with an

IP backbone may provide VPNs (Virtual Private Networks) for its

customers. MPLS (Multiprotocol Label Switching) is used for

forwarding packets over the backbone, and BGP (Border Gateway

Protocol) is used for distributing routes over the backbone. The

primary goal of this method is to support the outsourcing of IP

backbone services for enterprise networks. It does so in a manner

which is simple for the enterprise, while still scalable and flexible

for the Service Provider, and while allowing the Service Provider to

add value. These techniques can also be used to provide a VPN which

itself provides IP service to customers.

Table of Contents

1 Introduction ....................................... 2

1.1 Virtual Private Networks ........................... 2

1.2 Edge Devices ....................................... 3

1.3 VPNs with Overlapping Address Spaces ............... 4

1.4 VPNs with Different Routes to the Same System ...... 4

1.5 Multiple Forwarding Tables in PEs .................. 5

1.6 SP Backbone Routers ................................ 5

1.7 Security ........................................... 5

2 Sites and CEs ...................................... 6

3 Per-Site Forwarding Tables in the PEs .............. 6

3.1 Virtual Sites ...................................... 8

4 VPN Route Distribution via BGP ..................... 8

4.1 The VPN-IPv4 Address Family ........................ 9

4.2 Controlling Route Distribution ..................... 10

4.2.1 The Target VPN Attribute ........................... 10

4.2.2 Route Distribution Among PEs by BGP ................ 12

4.2.3 The VPN of Origin Attribute ........................ 13

4.2.4 Building VPNs using Target and Origin Attributes ... 14

5 Forwarding Across the Backbone ..................... 15

6 How PEs Learn Routes from CEs ...................... 16

7 How CEs learn Routes from PEs ...................... 19

8 What if the CE Supports MPLS? ...................... 19

8.1 Virtual Sites ...................................... 19

8.2 Representing ...