Editing IPv6 (section)

===Tunneling===
The technical basis for tunneling, or encapsulating IPv6 packets in IPv4 packets, is outlined in RFC 4213. When the Internet backbone was IPv4-only, one of the frequently used tunneling protocols was [[6to4]].<ref name="Steven J. Vaughan-Nichols">{{Cite news |last=Vaughan-Nichols |first=Steven J. |date=14 October 2010 |title=Five ways for IPv6 and IPv4 to peacefully co-exist |url=https://www.zdnet.com/home-and-office/networking/five-ways-for-ipv6-and-ipv4-to-peacefully-co-exist/ |url-status=live |archive-url=https://web.archive.org/web/20231205094000/https://www.zdnet.com/home-and-office/networking/five-ways-for-ipv6-and-ipv4-to-peacefully-co-exist/ |archive-date=5 December 2023 |access-date=13 March 2017 |work=[[ZDNET]] }}</ref> [[Teredo tunneling]] was also frequently used for integrating IPv6 LANs with the IPv4 Internet backbone. Teredo is outlined in RFC 4380 and allows IPv6 [[local area networks]] to tunnel over IPv4 networks, by encapsulating IPv6 packets within UDP. The Teredo relay is an IPv6 router that mediates between a Teredo server and the native IPv6 network. It was expected that 6to4 and Teredo would be widely deployed until ISP networks would switch to native IPv6, but by 2014 Google Statistics showed that the use of both mechanisms had dropped to almost 0.<ref>{{Cite book|title=IPv6 Essentials: Integrating IPv6 into Your IPv4 Network|author=Silvia Hagen|publisher=O'Reilly Media, Inc.|year=2014|isbn=9781449335267|pages=33}}</ref>