RFC 9977 - Publishing End-Site Prefix Lengths

• Status: Proposed Standard
• Published: May 2026
• Stream: IETF
• Errata: No Errata

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Abstract

This document specifies how to augment the RPSL inetnum: class to refer to prefixlen files, which are CSV files used to specify end-site prefix lengths. It also describes an optional RPKI-based mechanism for authenticating prefixlen files.

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Contents

• 1. Introduction
• 2. Requirements Language
• 3. prefixlen Files
• 4. inetnum: Class
• 5. Fetching prefixlen Data
• 6. Authenticating prefixlen Data (Optional)
• 7. Operational Considerations
• 8. Implementation Status
• 9. Security Considerations
• 10. IANA Considerations
• 11. References
• Appendix A. ASN.1 Module
• Appendix B. Example
• Acknowledgments
• Authors' Addresses

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Related Resources

• Official Text: RFC 9977
• Official Page: RFC 9977 DataTracker
• Errata: RFC Editor Errata