RFC 4861 - Neighbor Discovery for IP version 6 (IPv6)

Publication Date: September 2007
Status: Standards Track
Obsoletes: RFC 2461
Authors: T. Narten (IBM), E. Nordmark (Sun Microsystems), W. Simpson (Daydreamer), H. Soliman (Elevate Technologies)

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Abstract

This document specifies the Neighbor Discovery protocol for IP Version 6. IPv6 nodes on the same link use Neighbor Discovery to discover each other's presence, to determine each other's link-layer addresses, to find routers, and to maintain reachability information about the paths to active neighbors.

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Table of Contents

• 1. Introduction
• 2. Terminology
  • 2.1. General
  • 2.2. Link Types
  • 2.3. Addresses
  • 2.4. Requirements
• 3. Protocol Overview
  • 3.1. Comparison with IPv4
  • 3.2. Supported Link Types
  • 3.3. Securing Neighbor Discovery Messages
• 4. Message Formats
  • 4.1. Router Solicitation Message Format
  • 4.2. Router Advertisement Message Format
  • 4.3. Neighbor Solicitation Message Format
  • 4.4. Neighbor Advertisement Message Format
  • 4.5. Redirect Message Format
  • 4.6. Option Formats
• 5. Conceptual Model of a Host
  • 5.1. Conceptual Data Structures
  • 5.2. Conceptual Sending Algorithm
  • 5.3. Garbage Collection and Timeout Requirements
• 6. Router and Prefix Discovery
  • 6.1. Message Validation
  • 6.2. Router Specification
  • 6.3. Host Specification
• 7. Address Resolution and Neighbor Unreachability Detection
  • 7.1. Message Validation
  • 7.2. Address Resolution
  • 7.3. Neighbor Unreachability Detection
• 8. Redirect Function
  • 8.1. Validation of Redirect Messages
  • 8.2. Router Specification
  • 8.3. Host Specification
• 9. Extensibility - Option Processing
• 10. Protocol Constants
• 11. Security Considerations
  • 11.1. Threat Analysis
  • 11.2. Securing Neighbor Discovery Messages
• 12. Renumbering Considerations
• 13. IANA Considerations
• 14. References
  • 14.1. Normative References
  • 14.2. Informative References

Appendices

• Appendix A: Multihomed Hosts
• Appendix B: Future Extensions
• Appendix C: State Machine for the Reachability State
• Appendix D: Summary of IsRouter Rules
• Appendix E: Implementation Issues
• Appendix F: Changes from RFC 2461

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Related Resources

• Official Text: RFC 4861
• Official Page: RFC 4861 DataTracker
• Errata: RFC Editor Errata

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