The intersect Protocol (IP) is the first communications protocol in the intervene protocol suite for relaying datagrams above net boundaries. Its routingfunction enables internetworking, and in establishes the Internet.
IP has the role of delivering packets from the fountainhead multitude to the destination multitude solely based on the IP addresses in the packet headers. For this purpose, IP defines packet structures that encapsulate the figures to be delivered. It also defines addressing methods that are use to classification the datagram with well and destination information.
Historically, IP was the connectionless datagram rite in the creative Transmission Control Program introduced by Vint Cerf and Bob Kahn in 1974, which was complemented by a connection-oriented stint that became the justification for the Transmission Control Protocol (TCP). The intense protocol suite is so often referred to as TCP/IP.
The first senior report of IP, intent Protocol Version 4 (IPv4), is the master protocol of the Internet. Its successor is intern Protocol Version 6 (IPv6), which has been in swelling deployment on the open intersect since c. 2006.
The intercept Protocol is stable for addressing receive interfaces, encapsulating figures into datagrams (including fragmentation and reassembly) and routing datagrams from a inception ceremonies interface to a destination sacrament interface over one or more IP networks. For these purposes, the intervene Protocol defines the format of packets and provides an addressing system.
Each datagram has two components: a header and a payload. The IP header includes expert IP address, destination IP address, and other metadata needed to wandering and refer the datagram. The payload is the material that is transported. This formula of nesting the figures payload in a packet with a header is called encapsulation.
IP addressing entails the authorisation of IP addresses and associated parameters to a interfaces. The invoke expanse is divided into subnetworks, involving the designation of complication prefixes. IP routing is performed by all hosts, as well as routers, whose capital purpose is to transport packets beyond compound boundaries. Routers declare with one another via specially designed routing protocols, either interior gateway protocols or exterior gateway protocols, as needed for the topology of the network.
In May 1974, the Institute of Electrical and Electronics Engineers (IEEE) published a daily entitled “A Protocol for Packet Network Intercommunication”. The paper’s authors, Vint Cerf and Bob Kahn, described an internetworking protocol for sharing resources using packet switching among net nodes. A median monopolise inherent of this image was the “Transmission Control Program” that incorporated both connection-oriented links and datagram services between hosts. The monolithic Transmission Control Program was later divided into a modular architecture consisting of the Transmission Control Protocol and User Datagram Protocol at the transport covering and the intense Protocol at the internet layer. The example became known as the Department of Defense (DoD) interest Model andInternet protocol suite, and informally as TCP/IP.
IP versions 0 to 3 were experimental versions, use between 1977 and 1979. The ensuing intervene Experiment Note (IEN) documents summarise versions of the intercept Protocol prior to the present rendering of IPv4:
IEN 2 (Comments on intern Protocol and TCP), dated August 1977 describes the use to sever the TCP and intersect Protocol functionalities (which were erstwhile combined.) It proposes the first variant of the IP header, using 0 for the paraphrase field.
IEN 26 (A Proposed New interest Header Format), dated February 1978 describes a story of the IP header that uses a 1-bit variant field.
IEN 28 (Draft Internetwork Protocol Description Version 2), dated February 1978 describes IPv2.
IEN 41 (Internetwork Protocol Specification Version 4), dated June 1978 describes the first protocol to be called IPv4. The IP header is divergent from the immediate IPv4 header.
IEN 44 (Latest Header Formats), dated June 1978 describes another rendition of IPv4, also with a header manifold from the attendant IPv4 header.
IEN 54 (Internetwork Protocol Specification Version 4), dated September 1978 is the first narration of IPv4 using the header that would be standardized in RFC 760.
The controlling internetworking protocol in the intense Layer in use is IPv4; the collection 4 is the protocol report total carried in every IP datagram. IPv4 is described inInternet portal
IP forwarding algorithm
List of IP protocol numbers