Deploying Dual-Stack lite in IPv6-only Network

IETF76 Hiroshima

softwiredraft-boucadair-dslite-interco-v4v6-02

Pierre Lévis

pierre.levis@orange-ftgroup.com

7th November 2009

2

Introduction

I-D.boucadair-dslite-interco-v4v6

http://tools.ietf.org/html/draft-boucadair-dslite-interco-v4v6-02

Version 02 (01 presented in IETF75 Stockholm)

Authors/Contributors: M. Boucadair, C. Jacquenet, JL. Grimault, M. Kassi-Lahlou, P. Levis (France Telecom); D. Cheng (Huawei); Y. Lee ( Comcast)

Further to the comments received during IETF75 softwire session, we present here the main changes from 01 to 02:

– Difference with mesh– Routing considerations (Routing Architecture Example)

3

IPv4 and IPv6 Internet Connectivity

ISP

CPE: Customer Premises Equipment

CN: Correspondent Node

IPv4 Internet

CPE CNDS-lite CGNIPv6 IPv4

4

IPv4 and IPv6 Internet Connectivity

ISP

CPE: Customer Premises Equipment

CN: Correspondent Node

IPv4 Internet

CPE CNDS-lite CGNIPv6 IPv4

ISP IPv6 Internet

CPE CNIPv6

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A voluntary migration towards IPv6

ISPIPv4 or IPv6 Internet

IPv6-Only

CPE CN

6

IPv4 Internet Connectivitywith IPv6 in Access and Core

ISP IPv4 Internet

CPE CNDS-lite CGNIPv6 IPv6 IPv4

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IPv4 Internet Connectivitywith IPv6 in Access and Core

ISP

ICXF: Interconnection Function

IPv4 Internet

CPE CNDS-lite CGNIPv6 IPv6 ICXF IPv4

8

RFC5565 Mesh

IPv6 AFBR IPv4AFBRIPv4

– IPv4 tunneling through an IPv6-only backbone

– Interconnection function at the backbone's edge routers called AFBR

– All AFBRs exchange i-BGP routes

– The encapsulation at both sides uses a BGP-distributed route to retrieve the IPv6 destination address of the distant softwire endpoint

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Differences with RFC5565

ISP IPv4 Internet

CPE CNDS-lite CGNIPv6 IPv6 ICXF IPv4

– Asymmetry: CGNs, and IPv4 Internet access points. – Interconnection function at each IPv4 Internet access

point called ICXF– All ICXFs exchange i-BGP information, CGNs are not

compelled to participate in the i-BGP exchanges – The encapsulation at both sides is stateless; the IPv6

destination address of the distant softwire endpoint is automatically generated, it embeds the IPv4 destination address of the IPv4 datagram

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IPv4-in-IPv6 Stateless Encapsulation

IPv4 InternetDS-lite CGN

IPv6

ICXF

Stateless Encap Pref6+@IPv4 dest

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IPv4-in-IPv6 Stateless Encapsulation

IPv4 InternetDS-lite CGN

IPv6

ICXF

Stateless Encap Pref6+@IPv4 dest

Stateless Encap Pref6+@IPv4 dest

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A Routing Architecture Example

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Routing Architecture Example

IPv4 InternetDS-lite CGN

IPv6

ICXF

IPv4 BGP Advert:

• IPv4internal

ICXF

IPv4 Internet

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Routing Architecture Example

IPv4 InternetDS-lite CGN

IPv6

ICXF

IPv4 BGP Advert:

• IPv4internal

ICXF

IPv4 Interneti-BGP Advert:

•IPv4external

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Routing Architecture Example

IPv4 InternetDS-lite CGN

IPv6

ICXF

IPv4 BGP Advert:

• IPv4internal

ICXF

IPv4 Interneti-BGP Advert:

•IPv4external

Mesh-like

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Routing Architecture Example

IPv4 InternetDS-lite CGN

IPv6

ICXF

IPv4 BGP Advert:

• IPv4internal

ICXF

IPv4 Interneti-BGP Advert:

•IPv4external

IPv6 IGP Advert:

• Pref6

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Routing Architecture Example

IPv4 InternetDS-lite CGN

IPv6

ICXF

IPv4 BGP Advert:

• IPv4internal

ICXF

IPv4 Interneti-BGP Advert:

•IPv4external

IPv6 IGP Advert:

• Pref6

We do not inject external IPv4 routes

into IGP!

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Routing Architecture Example

IPv4 InternetDS-lite CGN

IPv6

ICXF

IPv4 BGP Advert:

• IPv4internal

ICXF

IPv4 Interneti-BGP Advert:

•IPv4external

IPv6 IGP Advert:

• Pref6

IPv6 IGP Advert:

•Pref6+IPv4(DS-lite pool)

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Routing Architecture Example

IPv4 InternetDS-lite CGN

IPv6

ICXF

IPv4 BGP Advert:

• IPv4internal

ICXF

IPv4 Interneti-BGP Advert:

•IPv4external

IPv6 IGP Advert:

• Pref6

IPv6 IGP Advert:

•Pref6+IPv4(DS-lite pool)

By the DS-lite CGN

or by a default router

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Routing Architecture Example

IPv4 InternetDS-lite CGN ICXF

ICXF

IPv4 Internet

IPv6

IPv4-in-IPv6

@IPv6dest = Pref6+@IPv4dest

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Routing Architecture Example

IPv4 InternetDS-lite CGN ICXF

ICXF

IPv4 Internet

IPv6

Goes to nearest ICXF (IPv6 IGP standpoint)

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Routing Architecture Example

IPv4 InternetDS-lite CGN ICXF

ICXF

IPv4 Internet

IPv6

Decap IPv4 packet

Lookup:

Best route is via another ICXF (mesh-like) or via an eBGP peer

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IPv4 InternetDS-lite CGN

ICXF

ICXF

IPv4 Internet

IPv6

DS-lite CGN

Internal communication

Routing Architecture Example

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Conclusion

Towards an IPv6-only ISP network Also suitable for IPv4 Core with IPv4-in-IPv6-in-IPv4 encapsulation This is an alternative to mesh

– IPv4-in-IPv6 encapsulations are stateless– DS-lite CGNs do not need to be i-BGP peers– The communication between DS-lite CGNs uses IPv6 transfer capabilities

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Question to the softwire WG

I-D.boucadair-dslite-interco-v4v6 "Deploying Dual-Stack lite in IPv6-only Network" as a Softwire WG document?

– We are requesting the adoption of this document as working group document

Thank You