Carrier-Grade NAT (CGN) Deployment with BGP/MPLS IP VPNs
RFC 7289
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Type |
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RFC - Informational
(June 2014; No errata)
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Last updated |
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2015-10-14
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Replaces |
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draft-kuarsingh-lsn-deployment
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Stream |
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IETF
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Formats |
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plain text
pdf
html
bibtex
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WG state
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Submitted to IESG for Publication
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Document shepherd |
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Melinda Shore
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Shepherd write-up |
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Show
(last changed 2013-09-29)
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| IESG |
IESG state |
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RFC 7289 (Informational)
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Consensus Boilerplate |
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Yes
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Telechat date |
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Responsible AD |
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Benoit Claise
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Send notices to |
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(None)
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| IANA |
IANA review state |
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Version Changed - Review Needed
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IANA action state |
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No IC
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Internet Engineering Task Force (IETF) V. Kuarsingh, Ed.
Request for Comments: 7289 J. Cianfarani
Category: Informational Rogers Communications
ISSN: 2070-1721 June 2014
Carrier-Grade NAT (CGN) Deployment with BGP/MPLS IP VPNs
Abstract
This document specifies a framework to integrate a Network Address
Translation (NAT) layer into an operator's network to function as a
Carrier-Grade NAT (also known as CGN or Large-Scale NAT). The CGN
infrastructure will often form a NAT444 environment as the subscriber
home network will likely also maintain a subscriber-side NAT
function. Exhaustion of the IPv4 address pool is a major driver
compelling some operators to implement CGN. Although operators may
wish to deploy IPv6 to strategically overcome IPv4 exhaustion, near-
term needs may not be satisfied with an IPv6 deployment alone. This
document provides a practical integration model that allows the CGN
platform to be integrated into the network, meeting the connectivity
needs of the subscriber while being mindful of not disrupting
existing services and meeting the technical challenges that CGN
brings. The model included in this document utilizes BGP/MPLS IP
VPNs, which allow for virtual routing separation, helping ease the
CGN's impact on the network. This document does not intend to defend
the merits of CGN.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7289.
Kuarsingh & Cianfarani Informational [Page 1]
RFC 7289 CGN Deployment with BGP/MPLS IP VPNs June 2014
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Kuarsingh & Cianfarani Informational [Page 2]
RFC 7289 CGN Deployment with BGP/MPLS IP VPNs June 2014
Table of Contents
1. Introduction ....................................................4
1.1. Acronyms and Terms .........................................4
2. Existing Network Considerations .................................5
3. CGN Network Deployment Requirements .............................5
3.1. Centralized versus Distributed Deployment ..................6
3.2. CGN and Traditional IPv4 Service Coexistence ...............7
3.3. CGN Bypass .................................................7
3.4. Routing Plane Separation ...................................8
3.5. Flexible Deployment Options ................................8
3.6. IPv4 Overlap Space .........................................9
3.7. Transactional Logging for CGN Systems ......................9
3.8. Base CGN Requirements ......................................9
4. BGP/MPLS IP VPN-Based CGN Framework .............................9
4.1. Service Separation ........................................11
4.2. Internal Service Delivery .................................12
4.2.1. Dual-Stack Operation ...............................14
4.3. Deployment Flexibility ....................................16
4.4. Comparison of BGP/MPLS IP VPN Option versus Other
CGN Attachment Options ....................................16
4.4.1. Policy-Based Routing ...............................16
4.4.2. Traffic Engineering ................................17
4.4.3. Multiple Routing Topologies ........................17
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