View source for IPv6 rapid deployment

{{Short description|Internet transition mechanism}}
[[File:6rd.svg|thumb|6rd]]
{{IPv6 transition mechanisms}}
'''6rd''' is a mechanism to facilitate '''IPv6 rapid  deployment''' across [[IPv4]] infrastructures of [[Internet service provider]]s (ISPs).

The protocol is derived from [[6to4]], a preexisting mechanism to transfer [[IPv6]] packets over the IPv4 network, with the significant change that it operates entirely within the end-user's ISP network, thus avoiding the major architectural problems inherent in the design of 6to4. The name 6rd is a reference to both the rapid deployments of IPv6 it enables, and, informally, the initials (RD) of its inventor,  [[Rémi Després]].

A description of 6rd principles and their first application by the ISP [[Free (ISP)|Free]] is published in RFC 5569,<ref name="RFC5569">RFC 5569 IPv6 Rapid Deployment on IPv4 Infrastructures (6rd)</ref> The 6rd specification prepared for [[Internet standard|standardization]] in the [[IETF]] is available as RFC 5969.<ref name="IETF">RFC 5969 IPv6 Rapid Deployment on IPv4 Infrastructures (6rd) -- Protocol Specification</ref>

== History ==
In November 2007, Rémi Després<ref>{{cite web
 | url=http://www.01net.com/editorial/320349/les-visionnaires/
 | title=Les visionnaires
 | language=fr
 | trans-title=Visionaries
 | access-date=2010-01-05
 | archive-date=2009-02-04
 | archive-url=https://web.archive.org/web/20090204234042/http://www.01net.com/editorial/320349/les-visionnaires/
 | url-status=dead
 }}</ref>&nbsp;— who was one of the creators of the [[Transpac (network)|Transpac]] data network in France in the 1970s&nbsp;— proposed to [[Free (ISP)|Free]], the second largest ISP in France, to use the 6rd mechanism he had invented to rapidly deploy IPv6. While Free had until then no short-term plan to offer IPv6 service, [[Rani Assaf]], the CTO of Free, immediately decided to implement the solution. Five weeks later,<ref name="IPv6 @ Free">{{cite web
 | url=http://ripe58.ripe.net/content/presentations/ipv6-free.pdf
 | title=IPv6 @ Free }}</ref> with due marketing approval and operational validation,  the press release<ref name="Free déploie l’IPv6">{{cite web
 | url=http://www.iliad.fr/presse/2007/CP_IPv6_121207.pdf
 | title=Free déploie l'IPv6 | language=fr
 |trans-title=Free deploys IPv6 }}</ref> announcing that IPv6 was available to Free's customers was issued.

The first draft describing the 6rd mechanism and Free's deployment was submitted to IETF on 9 February 2008.<ref>
{{cite news
 | url=http://tools.ietf.org/html/draft-despres-v6ops-6rd-ipv6-rapid-deployment-00
 | title=IPv6 Rapid Deployment on IPv4 infrastructures (6rd)
| newspaper=Ietf Datatracker
}} Initial draft</ref> After improvements, it was published on 24 January 2010 as informational RFC 5569.<ref name=RFC5569/>

In March 2010, a Working Group of the [[IETF]] approved that its latest draft on 6rd should become, after some more modifications, a [[Internet Standard|standards-track RFC]]. In August 2010, the standards-track RFC 5969<ref name="IETF"/> was published.
In October 2010 Comcast made 6rd software for home gateway devices available via open source for free.<ref>{{cite web
 | url=http://blog.comcast.com/2010/10/comcast-donates-additional-ipv6-open-source-software.html
 | title=Comcast releases open source 6rd software
}}</ref>

== Comparison to 6to4 ==
[[6to4]] works by relaying traffic between native [[IPv6]] and [[IPv4]] using relay servers which advertise common IPv4 and IPv6 prefixes to networks they are prepared to provide relay services for, but there is no guarantee that all native IPv6 hosts have a working route toward such a relay. Because of this, a 6to4 host is not guaranteed to be reachable by all native IPv6 hosts. Even when a relay is available, it is often operated by a third party who has no obligation to maintain a good [[quality of service]] as traffic grows. 6rd changes this model by making each [[internet service provider|ISP]] use one of its own IPv6 prefixes instead of the special {{IPaddr|2002::|16}} prefix standardized for 6to4,<ref>{{cite web |url=http://www.qacafe.com/knowledgebase/testing-6to4-and-6rd-ipv6-islands-with-cdrouter/ |title=What is 6to4, and how is 6rd an improvement? |access-date=2013-10-25 |archive-date=2018-10-24 |archive-url=https://web.archive.org/web/20181024192117/https://www.qacafe.com/knowledgebase/testing-6to4-and-6rd-ipv6-islands-with-cdrouter/ |url-status=dead }}</ref> so a provider is guaranteed that its 6rd hosts will be reachable from all native IPv6 hosts that can reach their IPv6 network. Because the relay is fully under the ISP's control, it keeps full responsibility for the quality of service for its customers.

Because 6rd relays can only be used by a limited set of hosts that are all under the control of the same administrative entity, it also reduces the scope for [[traffic anonymization]] attacks such as those possible with 6to4.<ref name=IETF/>

== Address space consumption ==
The simplest 6rd deployment, which uses 32 bits of IPv6 address space to map the entire IPv4 address space, consumes more address space than typical with IPv6 natively supported in all ISP routers. This can be mitigated by omitting redundant parts of the IPv4 address space, and in some cases by deploying multiple 6rd domains.<ref name=RFC5569 /><ref name=IETF />

The default allocation of IPv6 space by a [[regional Internet registry]] (RIR) is a 32-bit prefix. Since it takes 32 bits to map an IPv4 address with 6rd, this implies that an ISP would only be able to allocate 64-bit IPv6 prefixes to its customers if it were to use entire IPv4 addresses. 6rd, however, allows any redundant part of an IPv4 address to be discarded: For example, if the IPv4 addresses that an ISP issues to its customers all share the same first eighteen bits, a 6rd prefix only need include the remaining fourteen bits. Without this flexibility, [[Free (ISP)|Free]] originally assigned 64-bit IPv6 prefixes to its customers but was able to assign them shorter prefixes once it obtained a larger allocation of IPv6 space (a 26-bit prefix) from the [[RIPE NCC]].

== Current usage ==
{{Update section|date=February 2017}}
* [[Free (ISP)|Free]] has used 6rd since December 2007.<ref name="Free déploie l’IPv6"/> In 2008, a report from [[Google]] on its visibility of IPv6 use<ref>{{Cite web |url=http://www.ripe.net/ripe/meetings/ripe-57/presentations/Colitti-Global_IPv6_statistics_-_Measuring_the_current_state_of_IPv6_for_ordinary_users_.7gzD.pdf |title=''Global IPv6 Statistics - Measuring the current state of IPv6 for ordinary users'', Lorenzo Colitti (Google), RIPE 57 (Dubai, Oct 2008) |access-date=2010-03-30 |archive-date=2011-08-15 |archive-url=https://web.archive.org/web/20110815072414/http://meetings.ripe.net/ripe-57/presentations/Colitti-Global_IPv6_statistics_-_Measuring_the_current_state_of_IPv6_for_ordinary_users_.7gzD.pdf |url-status=dead }}</ref> showed France as having the second highest IPv6 penetration in the world, with 95% of its IPv6 being with "native" IPv6 addresses, almost all from Free.
* [[Comcast]] announced in January 2010 a trial using 6rd in the second quarter of 2010.<ref>{{cite web |url=https://arstechnica.com/tech-policy/news/2010/01/comcast-running-out-of-ipv4-addresses-beginning-ipv6-trial.ars |title=Comcast sees end of IPv4 tunnel, beginning IPv6 trial|date=29 January 2010 }}</ref> They began that 6RD trial on June 30, 2010, which was expected to ramp up to several hundred users in July 2010.<ref>{{cite web |url=http://www.comcast6.net |title=Comcast IPv6 Information Center}}</ref> But 6rd is not anticipated to be Comcast's primary IPv6 strategy.<ref>{{cite web |url=https://www.youtube.com/watch?v=lSsbJj4TVPM#t=51m0s  |archive-url=https://ghostarchive.org/varchive/youtube/20211220/lSsbJj4TVPM |archive-date=2021-12-20 |url-status=live|title=Google IPv6 Implementors Conference: Comcast IPv6 trials – John Jason Brzozowski, Comcast|website=[[YouTube]] }}{{cbignore}}</ref> Comcast has tested 2 different home gateways with 6rd, one of which they have made available via open source.<ref>{{cite web |url=http://blog.comcast.com/2010/10/comcast-donates-additional-ipv6-open-source-software.html |title=Comcast releases open source 6rd software}}</ref> In addition, they have published 6rd configuration instructions for any user on their network that wishes to use their 6rd border relays.<ref>{{cite web |url=http://www.comcast6.net/6rd-config.php |archive-url=https://web.archive.org/web/20101118035751/http://www.comcast6.net/6rd-config.php |url-status=dead |archive-date=2010-11-18 |title=How to configure 6rd for use on the Comcast network }}</ref> Comcast planned to deactivate their 6rd service on June 30, 2011 in anticipation of their wider deployment of native dual stack.<ref>{{cite web |url=http://www.comcast6.net/ |title=6RD Deactivation Planned}}</ref>
* [[Charter Communications|Charter]] has announced the planned deployment of 6rd across their network in 2012.<ref>{{cite web|url=http://www.charter.net/support/internet/ipv6/|title=IPv6}}</ref> They host a public 6rd border relay for their subscribers.
* The [[Linux kernel]] added support for 6rd in version 2.6.33.<ref>{{cite web |url=http://kernelnewbies.org/Linux_2_6_33#head-5fb916ab0f5afd77ff35436ea17b8d99520a3d33|title=ipv6 sit: 6rd (IPv6 Rapid Deployment) Support}}</ref>
* The Japanese company [[SoftBank]] have announced that they will begin rolling out IPv6 using 6rd.<ref>{{cite web |url=http://www.softbankbb.co.jp/ja/news/press/2010/20100223_01/ |title=IPv6インターネットサービスの提供について |language=ja |trans-title=IPv6 for Internet service |access-date=2010-02-25 |archive-date=2011-09-30 |archive-url=https://web.archive.org/web/20110930093905/http://www.softbankbb.co.jp/ja/news/press/2010/20100223_01/ |url-status=dead }}</ref>
* [[Swisscom]] is rolling out 6RD in 2011.<ref>{{cite web |url=http://labs.swisscom.ch/fr/news/ipv6-sneak-preview |title=Swisscom IPv6 sneak preview |access-date=2011-04-27 |archive-url=https://web.archive.org/web/20110430135121/http://labs.swisscom.ch/fr/news/ipv6-sneak-preview |archive-date=2011-04-30 |url-status=dead }}</ref> Starting 2022, Swisscom passed to a full dual stack approach.<ref>{{Cite web |title=Introduction DualStack for IPv6 {{!}} Swisscom |url=https://www.swisscom.ch/en/business/wholesale/ueberwholesale/aktuelles/dualstackipv6.html |access-date=2023-03-22 |website=www.swisscom.ch}}</ref>
* The Japanese company {{ill|SAKURA Internet|ja|さくらインターネット}} began its 6rd trial in March 2011.<ref>
{{cite web |url=http://www.sakura.ad.jp/news/archives/20110301-003.news |title=IPv6接続テストサービス「さくらの6rd」（トライアル）提供のお知らせ |language=ja |trans-title=IPv6 trial service using 6rd |url-status=dead |archive-url=https://web.archive.org/web/20110307033406/http://www.sakura.ad.jp/news/archives/20110301-003.news |archive-date=2011-03-07 }}</ref>
* Canadian ISP [[Videotron]] has deployed 6rd in beta on June 8, 2011 for customers using a 6rd-ready router.<ref>{{cite web |url=http://support.videotron.com/residential/internet/ipv6 |title=Videotron IPV6 FAQ |access-date=2011-07-31 |archive-date=2011-11-03 |archive-url=https://web.archive.org/web/20111103012721/http://support.videotron.com/residential/internet/ipv6 |url-status=dead }}</ref>
* In December 2011, Dutch ISP [[Telfort]] announced it was starting an IPv6 pre-pilot based on 6rd, inviting customers to participate. As of January 2013, 6rd is open as opt-in to all Telfort fixed line (ADSL and VDSL) customers. The "opt-in" means the customer has to enable 6RD in the Telfort Zyxel modem to get IPv6 connectivity.{{Citation needed|date=June 2013}} However this pilot has since been discontinued as parent company KPN shut down the Telfort subsidiary in 2019.
* [[CenturyLink]] has supported 6rd since April 2012 including a list of compatible modems.<ref>{{Cite web |url=http://qwest.centurylink.com/internethelp/static-ipv6-q.html |title=IPv6 FAQs |work=Qwest.CenturyLink.com |access-date=May 18, 2013 }}</ref>
* In January 2013, Dutch ISP [[ZeelandNet]] announced it was starting an IPv6 pre-pilot based on 6rd, inviting customers to participate. After the trial they expect to have a native/dual-stack solution on their [[EuroDOCSIS]] consumer network and business fiber network.<ref>{{cite web|url=http://www.martijnvandorst.nl/ipv6/testing/|title=ZeelandNet IPv6 Rapid Deployment test|access-date=2013-01-17|archive-date=2013-01-29|archive-url=https://web.archive.org/web/20130129044735/http://www.martijnvandorst.nl/ipv6/testing/|url-status=dead}} (in Dutch)</ref>
* As of June 12, 2013, Dutch ISP [[OnsBrabantNet]] supports 6rd on their network.{{Cite web|url=http://www.onsbrabantnet.nl/IPV6/|title=OnsBrabantNet website|date=June 2013|access-date=2018-07-07|archive-date=2014-10-06|archive-url=https://web.archive.org/web/20141006135421/http://www.onsbrabantnet.nl/IPV6/|url-status=dead}}
* In October 2013, Norwegian ISP [[Altibox]] announced that they offer IPv6 to 70,000 customers based on 6rd.<ref>{{cite web |url=http://www.altibox.no/nyheter?p_p_id=62_INSTANCE_fK9b&p_p_lifecycle=0&p_p_state=normal&p_p_mode=view&p_p_col_id=column-1&p_p_col_count=1&_62_INSTANCE_fK9b_struts_action=%2Fjournal_articles%2Fview&_62_INSTANCE_fK9b_groupId=10327&_62_INSTANCE_fK9b_articleId=7860137&_62_INSTANCE_fK9b_version=1.3 |title=70.000 kunder får tilbud om IPv6 |language=no |trans-title=70,000 customers are offered IPv6}}</ref> All customers who bypass the ISP's "home central" were able to use 6rd in March 2013, though it was only announced on a technician's Twitter account.<ref>{{cite web |url=https://twitter.com/finnsen/status/315810034779058176 |title=Tweet from @finnsen about Altibox' 6rd}}</ref>
* In November 2014, [[Sonic.net]] made 6rd available for subscribers with compatible equipment to choose to enable it.<ref>{{cite web |url=https://help.sonic.com/hc/en-us/articles/236083487-Fusion-IPv6-Tool |date=2021-11-13 |access-date=2022-04-11 |title=Fusion IPv6 Tool |work=help.sonic.com}}</ref>
* [[Telia Company]] is using 6rd.<ref>{{cite web | url=http://ipv6-test.com/stats/country/FI | title=Overall IPv6 and v4 protocol support in Finland}}</ref>
* Tweak, a Dutch fiber ISP, is using 6rd.<ref>{{cite web | url=https://www.tweak.nl/internet/ipv6.html | title=Tweak IPv6 wiki page}}</ref>
* [[Alaska Communications]], a [[telecommunications]] corporation headquartered in [[Alaska]], provides experimental support for 6rd to subscribers.<ref>{{cite web | url=https://6rd.acsalaska.net/6rd/ | title=Alaska Communications IPv6 Tunnels}}</ref>

== See also ==
* [[IPv6 deployment]]

== References ==
{{Reflist}}
* Adeel Ahmed, Salman Asadullah, ''Deploying  IPv6 in Broadband Access Networks'', John Wiley and Sons, 2009, {{ISBN|0-470-19338-7}}, pp.&nbsp;195&ndash;205

== External links ==
* [http://www.6deploy.eu/workshops2/20110405_santiago_compostela_spain/Jordi_130-6deploy_ipv6_transition_v0_8.pdf IPv4 and IPv6 Transition and Coexistence], 6DEPLOY project, 2011

[[Category:IPv6 transition technologies]]