Editing IPv6 (section)

===IPsec===
[[Internet Protocol Security]] (IPsec) was originally developed for IPv6, but found widespread deployment first in IPv4, for which it was re-engineered. IPsec was a mandatory part of all IPv6 protocol implementations,<ref name=rfc2460/> and [[Internet Key Exchange]] (IKE) was recommended, but with RFC 6434 the inclusion of IPsec in IPv6 implementations was downgraded to a recommendation because it was considered impractical to require full IPsec implementation for all types of devices that may use IPv6.{{ref RFC|6434|quote=Previously, IPv6 mandated implementation of IPsec and recommended the key management approach of IKE.  This document updates that recommendation by making support of the IPsec Architecture RFC4301 a SHOULD for all IPv6 nodes. |p=17}} However, as of RFC 4301 IPv6 protocol implementations that do implement IPsec need to implement IKEv2 and need to support a minimum set of [[Cryptography|cryptographic algorithms]]. This requirement will help to make IPsec implementations more interoperable between devices from different vendors. The IPsec Authentication Header (AH) and the Encapsulating Security Payload header (ESP) are implemented as IPv6 extension headers.<ref>{{Cite book|title=IPv6 Essentials: Integrating IPv6 into Your IPv4 Network|author=Silvia Hagen|publisher=O'Reilly Media|year=2014|isbn=978-1-4493-3526-7|page=196|edition=3rd|location=Sebastopol, CA|oclc=881832733}}</ref>