RFC 8955 - Dissemination of Flow Specification Rules

Obsoletes: RFC 5575, RFC 7674
Category: Standards Track
Published: December 2020

Abstract

This document defines a Border Gateway Protocol Network Layer Reachability Information (BGP NLRI) encoding format that can be used to distribute (intra-domain and inter-domain) traffic Flow Specifications for IPv4 unicast and IPv4 BGP/MPLS VPN services. This allows the routing system to propagate information regarding more specific components of the traffic aggregate defined by an IP destination prefix.

It also specifies BGP Extended Community encoding formats, which can be used to propagate Traffic Filtering Actions along with the Flow Specification NLRI. Those Traffic Filtering Actions encode actions a routing system can take if the packet matches the Flow Specification.

This document obsoletes both RFC 5575 and RFC 7674.

Contents

• 1. Introduction
• 2. Definitions of Terms Used in This Memo
• 3. Flow Specifications
• 4. Dissemination of IPv4 Flow Specification Information
  • 4.1. Length Encoding
  • 4.2. NLRI Value Encoding
    • 4.2.1. Operators
    • 4.2.2. Components
  • 4.3. Examples of Encodings
• 5. Traffic Filtering
  • 5.1. Ordering of Flow Specifications
• 6. Validation Procedure
• 7. Traffic Filtering Actions
  • 7.1. Traffic Rate in Bytes (traffic-rate-bytes) Sub-Type 0x06
  • 7.2. Traffic Rate in Packets (traffic-rate-packets) Sub-Type 0x0c
  • 7.3. Traffic-Action (traffic-action) Sub-Type 0x07
  • 7.4. RT Redirect (rt-redirect) Sub-Type 0x08
  • 7.5. Traffic Marking (traffic-marking) Sub-Type 0x09
  • 7.6. Interaction with Other Filtering Mechanisms in Routers
  • 7.7. Considerations on Traffic Filtering Action Interference
• 8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks
• 9. Traffic Monitoring
• 10. Error Handling
• 11. IANA Considerations
  • 11.1. AFI/SAFI Definitions
  • 11.2. Flow Component Definitions
  • 11.3. Extended Community Flow Specification Actions
• 12. Security Considerations
• 13. References
  • 13.1. Normative References
  • 13.2. Informative References
• Appendix A. Example Python code: flow_rule_cmp
• Appendix B. Comparison with RFC 5575
• Acknowledgments
• Contributors
• Authors' Addresses

Status of This Memo

This is an Internet Standards Track document.

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8955.

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