IPv6 packet: Difference between revisions

Revision as of 09:21, 9 July 2019

Revision as of 23:21, 21 September 2019

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An '''IPv6 packet''' is the smallest message entity exchanged via the Internet Protocol across an [[IPv6|Internet Protocol version 6 (IPv6)]] network.

[[PacketNetwork (information technology)packet|Packet]]s consist of control information for addressing and routing, and a [[payload (computing)|payload]] consisting of user data. The control information in IPv6 packets is subdivided into a mandatory fixed [[header (computing)|header]] and optional extension headers. The payload of an IPv6 packet is typically a [[datagram]] or segment of the higher-level [[Transport Layer]] protocol, but may be data for an [[Internet Layer]] (e.g., [[ICMPv6]]) or [[Link Layer]] (e.g., [[OSPF]]) instead.

IPv6 packets are typically transmitted over a [[Link Layer]] protocol, such as [[Ethernet]], which encapsulates each packet in a [[frame (networking)|frame]], but this may also be a higher layer [[tunneling protocol]], such as [[IPv4]] when using [[6to4]] or [[Teredo tunneling|Teredo]] transition technologies.

[[router (computing)|Router]]s do not fragment IPv6 packets, as they do for IPv4. [[Host (network)|Hosts]] are "strongly recommended"<ref name=rfc8200>{{Cite IETF|rfc=8200|title=Internet Protocol, Version 6 (IPv6) Specification|authorlink1=Steve Deering|author1=S. Deering|author2=R. Hinden|publisher=[[Internet Engineering Task Force]] (IETF)|date=July 2017}} Obsoletes RFC 2460.</ref> to implement [[Path MTU Discovery]] to take advantage of [[Maximum transmission unit|MTU]]s greater than the smallest MTU of 1280 [[octet (computing)|octets]]. A node may use the IPv6 Fragment header to fragment the packet at the source and have it reassembled at the destination(s).<ref name=rfc8200></ref>

Since July 2017, the [[Internet Assigned Numbers Authority]] (IANA) is responsible for registering all IPv6 parameters that are used in theIPv6 various IPv6packet headers.<ref name=rfc8200/>

==Fixed header==