RFC 1123

Network Working Group
Request for Comments: 1123

Internet Engineering Task Force
R. Braden, Editor
October 1989

Status of This Memo

This RFC is an official specification for the Internet community. It incorporates by reference, amends, corrects, and supplements the primary protocol standards documents relating to hosts. Distribution of this document is unlimited.

Summary

This RFC is one of a pair that defines and discusses the requirements for Internet host software. This RFC covers the application and support protocols; its companion RFC-1122 covers the communication protocol layers: link layer, IP layer, and transport layer.

Table of Contents

• 1. INTRODUCTION
  • 1.1 The Internet Architecture
  • 1.2 General Considerations
    • 1.2.1 Continuing Internet Evolution
    • 1.2.2 Robustness Principle
    • 1.2.3 Error Logging
    • 1.2.4 Configuration
  • 1.3 Reading this Document
    • 1.3.1 Organization
    • 1.3.2 Requirements
    • 1.3.3 Terminology
  • 1.4 Acknowledgments
• 2. GENERAL ISSUES
  • 2.1 Host Names and Numbers
  • 2.2 Using Domain Name Service
  • 2.3 Applications on Multihomed hosts
  • 2.4 Type-of-Service
  • 2.5 GENERAL APPLICATION REQUIREMENTS SUMMARY
• 3. REMOTE LOGIN -- TELNET PROTOCOL
  • 3.1 INTRODUCTION
  • 3.2 PROTOCOL WALK-THROUGH
    • 3.2.1 Option Negotiation: RFC-854, pp. 2-3
    • 3.2.2 Telnet Go-Ahead Function: RFC-854, p. 5, and RFC-858
    • 3.2.3 Control Functions: RFC-854, pp. 7-8
    • 3.2.4 Telnet
    • 3.2.5 NVT Printer and Keyboard: RFC-854, p. 11
    • 3.2.6 Telnet Command Structure: RFC-854, p. 13
    • 3.2.7 Telnet Binary Option: RFC-856
    • 3.2.8 Telnet Terminal-Type Option: RFC-1091
  • 3.3 SPECIFIC ISSUES
    • 3.3.1 Telnet End-of-Line Convention
    • 3.3.2 Data Entry Terminals
    • 3.3.3 Option Requirements
    • 3.3.4 Option Initiation
    • 3.3.5 Telnet Linemode Option
  • 3.4 TELNET/USER INTERFACE
    • 3.4.1 Character Set Transparency
    • 3.4.2 Telnet Commands
    • 3.4.3 TCP Connection Errors
    • 3.4.4 Non-Default Telnet Contact Port
    • 3.4.5 Flushing Output
  • 3.5. TELNET REQUIREMENTS SUMMARY
• 4. FILE TRANSFER
  • 4.1 FILE TRANSFER PROTOCOL -- FTP
    • 4.1.1 INTRODUCTION
    • 4.1.2. PROTOCOL WALK-THROUGH
      • 4.1.2.1 LOCAL Type: RFC-959 Section 3.1.1.4
      • 4.1.2.2 Telnet Format Control: RFC-959 Section 3.1.1.5.2
      • 4.1.2.3 Page Structure: RFC-959 Section 3.1.2.3 and Appendix I
      • 4.1.2.4 Data Structure Transformations: RFC-959 Section 3.1.2
      • 4.1.2.5 Data Connection Management: RFC-959 Section 3.3
      • 4.1.2.6 PASV Command: RFC-959 Section 4.1.2
      • 4.1.2.7 LIST and NLST Commands: RFC-959 Section 4.1.3
      • 4.1.2.8 SITE Command: RFC-959 Section 4.1.3
      • 4.1.2.9 STOU Command: RFC-959 Section 4.1.3
      • 4.1.2.10 Telnet End-of-line Code: RFC-959, Page 34
      • 4.1.2.11 FTP Replies: RFC-959 Section 4.2, Page 35
      • 4.1.2.12 Connections: RFC-959 Section 5.2
      • 4.1.2.13 Minimum Implementation; RFC-959 Section 5.1
    • 4.1.3 SPECIFIC ISSUES
      • 4.1.3.1 Non-standard Command Verbs
      • 4.1.3.2 Idle Timeout
      • 4.1.3.3 Concurrency of Data and Control
      • 4.1.3.4 FTP Restart Mechanism
    • 4.1.4 FTP/USER INTERFACE
      • 4.1.4.1 Pathname Specification
      • 4.1.4.2 QUOTE Command
      • 4.1.4.3 Displaying Replies to User
      • 4.1.4.4 Maintaining Synchronization
    • 4.1.5 FTP REQUIREMENTS SUMMARY
  • 4.2 TRIVIAL FILE TRANSFER PROTOCOL -- TFTP
    • 4.2.1 INTRODUCTION
    • 4.2.2 PROTOCOL WALK-THROUGH
      • 4.2.2.1 Transfer Modes: RFC-783, Page 3
      • 4.2.2.2 UDP Header: RFC-783, Page 17
    • 4.2.3 SPECIFIC ISSUES
      • 4.2.3.1 Sorcerer's Apprentice Syndrome
      • 4.2.3.2 Timeout Algorithms
      • 4.2.3.3 Extensions
      • 4.2.3.4 Access Control
      • 4.2.3.5 Broadcast Request
    • 4.2.4 TFTP REQUIREMENTS SUMMARY
• 5. ELECTRONIC MAIL -- SMTP and RFC-822
  • 5.1 INTRODUCTION
  • 5.2 PROTOCOL WALK-THROUGH
    • 5.2.1 The SMTP Model: RFC-821 Section 2
    • 5.2.2 Canonicalization: RFC-821 Section 3.1
    • 5.2.3 VRFY and EXPN Commands: RFC-821 Section 3.3
    • 5.2.4 SEND, SOML, and SAML Commands: RFC-821 Section 3.4
    • 5.2.5 HELO Command: RFC-821 Section 3.5
    • 5.2.6 Mail Relay: RFC-821 Section 3.6
    • 5.2.7 RCPT Command: RFC-821 Section 4.1.1
    • 5.2.8 DATA Command: RFC-821 Section 4.1.1
    • 5.2.9 Command Syntax: RFC-821 Section 4.1.2
    • 5.2.10 SMTP Replies: RFC-821 Section 4.2
    • 5.2.11 Transparency: RFC-821 Section 4.5.2
    • 5.2.12 WKS Use in MX Processing: RFC-974, p. 5
    • 5.2.13 RFC-822 Message Specification: RFC-822 Section 4
    • 5.2.14 RFC-822 Date and Time Specification: RFC-822 Section 5
    • 5.2.15 RFC-822 Syntax Change: RFC-822 Section 6.1
    • 5.2.16 RFC-822 Local-part: RFC-822 Section 6.2
    • 5.2.17 Domain Literals: RFC-822 Section 6.2.3
    • 5.2.18 Common Address Formatting Errors: RFC-822 Section 6.1
    • 5.2.19 Explicit Source Routes: RFC-822 Section 6.2.7
  • 5.3 SPECIFIC ISSUES
    • 5.3.1 SMTP Queueing Strategies
      • 5.3.1.1 Sending Strategy
      • 5.3.1.2 Receiving strategy
    • 5.3.2 Timeouts in SMTP
    • 5.3.3 Reliable Mail Receipt
    • 5.3.4 Reliable Mail Transmission
    • 5.3.5 Domain Name Support
    • 5.3.6 Mailing Lists and Aliases
    • 5.3.7 Mail Gatewaying
    • 5.3.8 Maximum Message Size
  • 5.4 SMTP REQUIREMENTS SUMMARY
• 6. SUPPORT SERVICES
  • 6.1 DOMAIN NAME TRANSLATION
    • 6.1.1 INTRODUCTION
    • 6.1.2 PROTOCOL WALK-THROUGH
      • 6.1.2.1 Resource Records with Zero TTL: RFC-1035 Section 3.2.1
      • 6.1.2.2 QCLASS Values: RFC-1035 Section 3.2.5
      • 6.1.2.3 Unused Fields: RFC-1035 Section 4.1.1
      • 6.1.2.4 Compression: RFC-1035 Section 4.1.4
      • 6.1.2.5 Misusing Configuration Info: RFC-1035 Section 6.1.2
    • 6.1.3 SPECIFIC ISSUES
      • 6.1.3.1 Resolver Implementation
      • 6.1.3.2 Transport Protocols
      • 6.1.3.3 Efficient Resource Usage
      • 6.1.3.4 Multihomed Hosts
      • 6.1.3.5 Extensibility
      • 6.1.3.6 Status of RR Types
      • 6.1.3.7 Robustness
      • 6.1.3.8 Local Host Table
    • 6.1.4 DNS USER INTERFACE
      • 6.1.4.1 DNS Administration
      • 6.1.4.2 DNS User Interface
      • 6.1.4.3 Interface Abbreviation Facilities
    • 6.1.5 DOMAIN NAME SYSTEM REQUIREMENTS SUMMARY
  • 6.2 HOST INITIALIZATION
    • 6.2.1 INTRODUCTION
    • 6.2.2 REQUIREMENTS
      • 6.2.2.1 Dynamic Configuration
      • 6.2.2.2 Loading Phase
  • 6.3 REMOTE MANAGEMENT
    • 6.3.1 INTRODUCTION
    • 6.3.2 PROTOCOL WALK-THROUGH
    • 6.3.3 MANAGEMENT REQUIREMENTS SUMMARY
• 7. REFERENCES
• Security Considerations
• Author's Address

• Original text document
• Complete HTML RFC (TAR, TGZ, or ZIP format)