IETF RFC 6888

IETF RFC 6888
Title	IETF RFC 6888
Issued	April 2013
Authors	Brian Haberman, Noel Chiappa
Organization	Internet Engineering Task Force
Pages	18
Status	Best Current Practice

IETF RFC 6888 is a Best Current Practice document from the Internet Engineering Task Force addressing IPv4 address sharing techniques and transition strategies among network operators and standards bodies such as the Internet Assigned Numbers Authority, the American Registry for Internet Numbers, and regional registries like RIPE NCC and APNIC. It situates technical guidance within operational contexts familiar to communities around the Internet Architecture Board, the Internet Engineering Steering Group, and working groups such as the IETF v6ops and is intended for implementers at organizations including Cisco Systems, Juniper Networks, and network operators represented by NANOG. The document builds on prior work from the United States Department of Commerce, the National Telecommunications and Information Administration, and academic contributors associated with institutions like MIT and Stanford.

Overview

RFC 6888 summarizes recommended practices for deploying address-sharing mechanisms such as Carrier-Grade NAT in environments influenced by policymakers at the Federal Communications Commission and standards contributors from the European Telecommunications Standards Institute and the International Telecommunication Union. It references operational concerns documented by the World Wide Web Consortium and research from universities including Carnegie Mellon University, University of California Berkeley, and Georgia Institute of Technology while aligning with activities at industry consortia like the Broadband Forum and the Open Networking Foundation. The document frames its guidance against historical milestones such as IPv6 development discussions at the IETF, operational events involving Akamai Technologies and Cloudflare, and deployment case studies from operators like AT&T and Deutsche Telekom.

Background and Motivation

The background traces IPv4 exhaustion narratives tied to allocations by IANA and policy decisions at ARIN, RIPE NCC, APNIC, LACNIC, and AFRINIC, and notes technical pressures described in earlier RFCs discussed at the IAB and IETF plenaries attended by authors from Google, Microsoft, and Facebook. Motivations include operational realities experienced by Internet service providers like Comcast and Verizon, regulatory considerations debated before the European Commission and national telecom regulators, and research findings published by Internet measurement projects at CAIDA and ISI. The motivation also references protocols and technologies such as DHCP, BGP, and DNS that interact with address-sharing solutions, and historical transitions exemplified by the adoption paths of TCP/IP in projects like DARPA and NSFNET.

Specification and Key Provisions

The specification section presents guidance on Carrier-Grade NAT deployment models, including address-sharing patterns, port-symmetric mappings, and logging practices that intersect with standards from the IETF, ETSI, and 3GPP. Key provisions advise on operational parameters, customer impact mitigation, and STUN/TURN interaction, drawing on implementations from vendors such as Cisco Systems, Juniper Networks, and Fortinet and referencing software projects like ISC DHCP and BIND. It prescribes recommendations for auditing, monitoring, and customer support aligned with practices in enterprises like IBM and HP, and references interoperability concerns raised by developers at Mozilla, Opera Software, and the Apache Software Foundation.

Implementation Considerations

Implementation guidance emphasizes coordination among network operators, equipment manufacturers, and service providers including Sprint, T-Mobile, and Vodafone, and highlights measurement and troubleshooting methods used by teams at measurement labs like RIPE Atlas and the Measurement Lab project. Considerations include impact on applications maintained by companies such as Amazon, Netflix, and Google, effects on protocols standardized by the IETF and 3GPP, and deployment lessons learned from content delivery networks like Akamai and Fastly. The section also addresses software toolchains and platforms used by operators, referencing projects at Red Hat, Canonical, and the OpenStack community.

Security and Privacy Considerations

Security and privacy discussion outlines the implications of address-sharing on audit trails, forensics, and lawful intercept processes involving agencies such as the Department of Justice and oversight bodies like the European Data Protection Supervisor, and references legal frameworks enforced by courts and legislatures. It assesses risks identified by security researchers from CERT/CC, SANS Institute, and academic groups at ETH Zurich and University of Cambridge, and discusses mitigation measures inspired by standards from the Internet Engineering Task Force, the National Institute of Standards and Technology, and ISO. The section also notes privacy concerns raised by advocacy organizations such as the Electronic Frontier Foundation and Human Rights Watch.

Adoption and Impact

Adoption narratives describe operational experiences from major service providers including Comcast, BT Group, and Telstra, industry responses from vendors like Huawei and Ericsson, and analysis by research organizations such as CAIDA and the Internet Society. The impact spans effects on content providers including Netflix and YouTube, measurement initiatives at RIPE NCC and APNIC, and policy discourse at bodies like the United Nations Broadband Commission and the OECD. The document influenced subsequent operational best practices, vendor feature sets, and discussions in IETF working groups and operator forums including NANOG and APRICOT.

Category:Internet standards Category:Internet Engineering Task Force