{"draft":"draft-ietf-idr-bgp-car-16","doc_id":"RFC9871","title":"BGP Color-Aware Routing (CAR)","authors":["D. Rao, Ed.","S. Agrawal, Ed."],"format":["HTML","TEXT","PDF","XML"],"page_count":"76","pub_status":"EXPERIMENTAL","status":"EXPERIMENTAL","source":"Inter-Domain Routing","abstract":"This document describes a BGP-based routing solution to establish\r\nend-to-end intent-aware paths across a multi-domain transport\r\nnetwork. The transport network can span multiple service provider and\r\ncustomer network domains. The BGP intent-aware paths can be used to\r\nsteer traffic flows for service routes that need a specific intent.\r\nThis solution is called BGP Color-Aware Routing (BGP CAR). \r\n\r\nThis document describes the routing framework and BGP extensions to\r\nenable intent-aware routing using the BGP CAR solution. The solution\r\ndefines two new BGP SAFIs (BGP CAR SAFI and BGP VPN CAR SAFI) for\r\nIPv4 and IPv6. It also defines an extensible Network Layer\r\nReachability Information (NLRI) model for both SAFIs that allows\r\nmultiple NLRI types to be defined for different use cases.  Each type\r\nof NLRI contains key and TLV-based non-key fields for efficient\r\nencoding of different per-prefix information. This specification\r\ndefines two NLRI types: Color-Aware Route NLRI and IP Prefix NLRI. It\r\ndefines non-key TLV types for the MPLS label stack, SR-MPLS label\r\nindex, and Segment Routing over IPv6 (SRv6) Segment Identifiers\r\n(SIDs). This solution also defines a new Local Color Mapping (LCM)\r\nExtended Community.","pub_date":"November 2025","keywords":["intent-aware routing","intent-based routing","color-aware VPNs","color-aware BGP transport","BGP extensible NLRI"],"obsoletes":[],"obsoleted_by":[],"updates":[],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC9871","errata_url":null}