{
  "$schema": "/api/schemas/documents.schema.json",
  "apiVersion": "1.1.0",
  "lastModified": "2026-10-20T21:14:59.331Z",
  "sourcePath": "src/main/data/docs",
  "docId": "RFC6751",
  "document": {
    "abstract": "In customer sites having IPv4-only Customer Premises Equipment (CPE), Teredo (RFC 4380, RFC 5991, RFC 6081) provides last-resort IPv6 connectivity. However, because it is designed to work without the involvement of Internet Service Providers, it has significant limitations (connectivity between IPv6 native addresses and Teredo addresses is uncertain; connectivity between Teredo addresses fails for some combinations of NAT types). 6a44 is a complementary solution that, being based on ISP cooperation, avoids these limitations. At the beginning of 6a44 IPv6 addresses, it replaces the Teredo well-known prefix, present at the beginning of Teredo IPv6 addresses, with network-specific /48 prefixes assigned by local ISPs (an evolution similar to that from 6to4 to 6rd (IPv6 Rapid Deployment on IPv4 Infrastructures)). The specification is expected to be complete enough for running code to be independently written and the solution to be incrementally deployed and used. This document defines an Experimental Protocol for the Internet community.",
    "abstract$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML abstract",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "authors": [
      {
        "name": "Rémi Després"
      },
      {
        "name": "Brian E. Carpenter"
      },
      {
        "name": "Dan Wing"
      },
      {
        "name": "Sheng Jiang"
      }
    ],
    "authors$meta": {
      "confidence": "high",
      "note": "Parsed from Datatracker doc page article:author (profile full names)",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "docId": "RFC6751",
    "docId$meta": {
      "confidence": "high",
      "note": "Derived from RFC number or Datatracker identifier",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "docLabel": "IETF RFC 6751",
    "docLabel$meta": {
      "confidence": "high",
      "note": "Constructed from provider and document identifier",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "docNumber": "6751",
    "docNumber$meta": {
      "confidence": "high",
      "note": "From the RFC index entry (rfc-index.xml <doc-id>)",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "docTitle": "Native IPv6 behind IPv4-to-IPv4 NAT Customer Premises Equipment (6a44)",
    "docTitle$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML title",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "docType": "Experimental",
    "docType$meta": {
      "confidence": "high",
      "note": "Mapped from Datatracker std_level or RFC status text",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "doi": "10.17487/RFC6751",
    "doi$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML doi",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "href": "https://doi.org/10.17487/RFC6751",
    "href$meta": {
      "confidence": "high",
      "note": "Derived from DOI (https://doi.org/<doi>)",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "keywords": [
      "Coexistence",
      "Interworking",
      "Tunnel",
      "Encapsulation",
      "LISP"
    ],
    "keywords$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML keywords",
      "originalValue": [
        "Coexistence",
        "Interworking",
        "Tunnel",
        "Encapsulation",
        "Map-and-encap",
        "Global Addressing"
      ],
      "overridden": true,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T21:14:59.331Z",
      "version": "extractDocs.js@commit:2d729ed26f61"
    },
    "pages": "33",
    "pages$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML page-count",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "publicationDate": "2012-10-01",
    "publicationDate$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML date",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "publisher": "IETF",
    "publisher$meta": {
      "confidence": "high",
      "note": "Static: provider",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "references": {
      "bibliographic": [
        "RFC1918",
        "RFC2827",
        "RFC3053",
        "RFC3056",
        "RFC3068",
        "RFC3704",
        "RFC4193",
        "RFC4380",
        "RFC4443",
        "RFC5245",
        "RFC5569",
        "RFC5626",
        "RFC5969",
        "RFC5991",
        "RFC6081",
        "RFC6145",
        "RFC6324",
        "orphan/RFC6751/h:c8d37666",
        "orphan/RFC6751/h:c8672697",
        "orphan/RFC6751/h:37c48e74",
        "orphan/RFC6751/h:da9ebc9d"
      ],
      "bibliographic$meta": {
        "confidence": "medium",
        "flag": "MIXED_REF_LAYOUT_RISK anchored=24 proseBlocks=30 skippedAnchorBlocks=28",
        "note": "Parsed from RFC HTML references/informative sections",
        "originalValue": [],
        "reviewRequired": true,
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
        "updated": "2026-10-20T17:30:10.018Z",
        "version": "extractDocs.js@commit:8277ba975118"
      },
      "normative": [
        "RFC792",
        "RFC2119",
        "RFC2460",
        "RFC4291"
      ],
      "normative$meta": {
        "confidence": "high",
        "note": "Parsed from RFC HTML normative references sections",
        "originalValue": [],
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
        "updated": "2026-10-20T17:30:10.018Z",
        "version": "extractDocs.js@commit:8277ba975118"
      }
    },
    "resolvedHref": "https://www.rfc-editor.org/info/rfc6751/",
    "resolvedHref$meta": {
      "confidence": "high",
      "note": "Final URL resolved via URL redirect verification",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
      "updated": "2026-10-20T17:30:10.017Z",
      "version": "extractDocs.js@commit:8277ba975118"
    },
    "status": {
      "active": true,
      "active$meta": {
        "confidence": "high",
        "note": "Derived from supersession relationship fields",
        "originalValue": null,
        "source": "resolved",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
        "updated": "2026-10-20T17:30:10.017Z",
        "version": "extractDocs.js@commit:8277ba975118"
      },
      "errataExist": true,
      "errataExist$meta": {
        "confidence": "high",
        "note": "Derived from presence of errata links on RFC/Datatracker pages",
        "originalValue": null,
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
        "updated": "2026-10-20T17:30:10.017Z",
        "version": "extractDocs.js@commit:8277ba975118"
      },
      "errataUrl": [
        "https://www.rfc-editor.org/errata/rfc6751",
        "https://www.rfc-editor.org/errata_search.php?rfc=6751",
        "https://www.rfc-editor.org/rfc/inline-errata/rfc6751.html"
      ],
      "errataUrl$meta": {
        "confidence": "high",
        "note": "Parsed from errata links on RFC/Datatracker pages",
        "originalValue": [],
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
        "updated": "2026-10-20T17:30:10.018Z",
        "version": "extractDocs.js@commit:8277ba975118"
      },
      "latestVersion": true,
      "latestVersion$meta": {
        "confidence": "high",
        "note": "Derived from supersession relationship fields",
        "originalValue": null,
        "source": "resolved",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
        "updated": "2026-10-20T17:30:10.017Z",
        "version": "extractDocs.js@commit:8277ba975118"
      },
      "statusNote": "Experimental",
      "statusNote$meta": {
        "confidence": "high",
        "note": "Mapped from Datatracker doc.json std_level",
        "originalValue": null,
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
        "updated": "2026-10-20T17:30:10.017Z",
        "version": "extractDocs.js@commit:8277ba975118"
      },
      "superseded": false,
      "superseded$meta": {
        "confidence": "high",
        "note": "Derived from supersession relationship fields",
        "originalValue": null,
        "source": "resolved",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc6751/",
        "updated": "2026-10-20T17:30:10.017Z",
        "version": "extractDocs.js@commit:8277ba975118"
      }
    }
  }
}