RFC 959 - FILE TRANSFER PROTOCOL (FTP)

Authors:

• J. Postel (ISI)
• J. Reynolds (ISI)

Date: October 1985
Obsoletes: RFC 765 (IEN 149)
Status: Standard Protocol

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Status of this Memo

This memo is the official specification of the File Transfer Protocol (FTP). Distribution of this memo is unlimited.

The following new optional commands are included in this edition of the specification:

• CDUP (Change to Parent Directory)
• SMNT (Structure Mount)
• STOU (Store Unique)
• RMD (Remove Directory)
• MKD (Make Directory)
• PWD (Print Directory)
• SYST (System)

Note that this specification is compatible with the previous edition.

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Abstract

The objectives of FTP are 1) to promote sharing of files (computer programs and/or data), 2) to encourage indirect or implicit (via programs) use of remote computers, 3) to shield a user from variations in file storage systems among hosts, and 4) to transfer data reliably and efficiently. FTP, though usable directly by a user at a terminal, is designed mainly for use by programs.

The attempt in this specification is to satisfy the diverse needs of users of maxi-hosts, mini-hosts, personal workstations, and TACs, with a simple, and easily implemented protocol design.

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Contents

• 1. Introduction
• 2. Overview
  • 2.1 History
  • 2.2 Terminology
  • 2.3 FTP Model
• 3. Data Transfer Functions
  • 3.1 Data Representation and Storage
  • 3.2 Establishing Data Connections
  • 3.3 Data Connection Management
  • 3.4 Transmission Modes
  • 3.5 Error Recovery and Restart
• 4. File Transfer Functions
  • 4.1 FTP Commands
  • 4.2 FTP Replies
• 5. Declarative Specifications
  • 5.1 Minimum Implementation
  • 5.2 Connections
  • 5.3 Commands
  • 5.4 Sequencing of Commands and Replies
• 6. State Diagrams
• 7. Typical FTP Scenario
• 8. Connection Establishment

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Related Resources

• Official Text: https://www.rfc-editor.org/rfc/rfc959.txt
• Official Page: https://datatracker.ietf.org/doc/html/rfc959

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