RFC 791 · September 1981 · J. Postel
Internet Protocol
Index fetched 2026-10-19 from rfc-editor.org
How it works
Built by hand from RFC 791. Every arrow, step and field cites the RFC sentence it comes from, and an automated test checks each quote against the RFC text. Provisional: not yet reviewed by a second engineer. Help verify this visual
RFC 791 §3.1 A summary of the contents of the internet header follows:
Version · 4 bits
Tells the receiver which header format follows. This RFC describes version 4.
Version: 4 bits The Version field indicates the format of the internet header. This document describes version 4.
Not shown: Type of Service sub-fields (precedence, D, T, R bits) and precedence values; Option formats and individual options (security, source routing, record route, stream ID, timestamp); Fragmentation and reassembly procedures (§3.2); Addressing and address classes (§3.2); Interfaces to higher-level protocols (§3.3).
Lineage
Text
Loading the RFC text…