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UpdatedINTERNET STANDARDLegacy streamSTD5

RFC 791: Internet Protocol

Still current, but amended. Parts of this document are changed or extended by RFC 1349, RFC 2474, RFC 6864. Read both.

In plain English — editorial summary, not part of the RFC

RFC 791 defines the Internet Protocol (IPv4) — the addressing and packet format that everything else on the internet rides on. It specifies the 32-bit address, the IP header (version, TTL, protocol, checksum, source and destination), and how packets are fragmented and reassembled when a link cannot carry them whole. IP itself promises nothing about delivery: it is best-effort, connectionless and unreliable by design, leaving reliability to TCP above it.

Document record

Document ID
RFC791
Published
September 1981
Authors
J. Postel
Status
INTERNET STANDARD
Stream
Legacy
Area
—
Pages
51
Also known as
STD5
Obsoletes:
RFC 760
Updated by:
RFC 1349, RFC 2474, RFC 6864

Topics

Referenced by

3 later RFCs formally update or obsolete part of this document.

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About this page

The document record above — title, authors, date, status, stream, area, relationships, DOI and errata — is imported verbatim from the public RFC Editor index. The “in plain English” section is editorial: written by The metasystema editorial team, not part of the RFC. Where the two differ, the RFC text governs.

Last checked against the RFC Editor index on . RFCs are never revised after publication; changes are issued as new documents.

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canonical URL: /rfc/791-internet-protocol