Internet-Draft Generalized RPSL External Reference October 2024
Bush Expires 24 April 2025 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-ymbk-opsawg-rpsl-extref-01
Published:
Intended Status:
Standards Track
Expires:
Author:
R. Bush
IIJ Research & Arrcus

Generalized RPSL External Reference

Abstract

RPSL, which has operationally evolved since it was standardized in 1999, has recently added a geofeed: attribute to the innet[6]num: class to reference data external to RPSL. There is now a proposal add another attribute referencing external data, prefixlen:. This document describes a more general and extensible mechanism for external references.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on 24 April 2025.

Table of Contents

1. Introduction

The Routing Policy Specification Language (RPSL), which has operationally evolved since standardization in [RFC2622], has recently added a geofeed: attribute [RFC9632] to the inetnum: [INETNUM] and inet6num: [INET6NUM] classes to reference data external to RPSL. There is now a proposal add another attribute, prefixlen: [I-D.gasser-opsawg-prefix-lengths] referencing exterbal data.

This document describes a more general and extensible mechanism for external references to augment the RPSL inetnum: class [INETNUM] to refer to external data. In all places inetnum:, [INETNUM], is used, inet6num:, [INET6NUM], should also be assumed.

1.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

2. Existing External References

RPSL, [RFC2622], as used by the Regional Internet Registries (RIRs), has been augmented with the inetnum: [INETNUM] and the inet6num: [INET6NUM] classes; each of which describes an IP address range and its attributes.

Ongoing work has added and/or proposes to add multiple attributes to RPSL to reference objects external to RPSL.

[RFC9632] descrbes how to reference geofeed files ([RFC8805]) from an RPSL inetnum: class. It is widely deployed.

[I-D.gasser-opsawg-prefix-lengths] proposes to refrence prefixlen files from an RPSL inetnum: class.

This way lies chaos. Where there are two, there will be more. This will cause continuing problems for work such as [I-D.ietf-regext-rdap-geofeed].

3. inetnum: Class

This document describes a generalized mechanism for external references. RPSL would be augmented to define a new RPSL extref: attribute in the inetnum: class. For example, given the two sub-types described above:

    inetnum: 192.0.2.0/24 # example
    extref: Geofeed https://example.com/geofeed
    extref: Prefixlen https://example.com/prefixlen

Any particular inetnum: class MAY have at most one extref: of a particular sub-type.

inetnum: classes form a hierarchy, see [INETNUM] Section 4.2.4.1, Hierarchy of INETNUM Objects. extref references SHOULD be at the lowest applicable inetnum: class. When fetching, the most specific inetnum: class with an extref reference of a particular sub-type MUST be used.

When extref: references are provided by multiple inetnum: classes which have identical address ranges, then the extref: reference on the inetnum: with the most recent last-modified: attribute SHOULD be preferred.

4. Operational Considerations

To create the needed inetnum: classes, an operator wishing to register extref: attributes needs to coordinate with their RIR/NIR and/or any provider LIR which has assigned prefixes to them. RIRs/NIRs provide means for assignees to create and maintain inetnum: classes. They also provide means of [sub-]assigning IP address resources and allowing the assignee to create whois data, including inetnum: classes, and thereby using extref: attributes.

For a particular sub-type, the RFC defining it SHOULD specify the transport over which the reference SHOULD or MUST be fetched.

Multiple inetnum: classes MAY refer to the same external resource.

5. Security Considerations

It would be generally prudent for a consumer of extref data to also use other sources to cross-validate the data. All of the Security Considerations of the RFC defining a sub-type apply here as well.

Many RPSL repositories have weak if any authentication. This would allow spoofing of inetnum: classes pointing to malicious extref files.

If an inetnum: for a wide prefix (e.g. a /16) points to an external file, a customer or attacker could publish an equal or narrower (e.g. a /24) inetnum: in a whois registry which has weak authorization.

The RPSL providers have had to throttle fetching from their servers due to too-frequent queries. Usually they throttle by the querying IP address or block. Similar defenses will likely need to be deployed by extref file servers.

Directing users and programs to external data has legal and technical risk exposure. Hence adding to the IANA SubTypee registry requires an RFC. One should still be cautious following links to or using external data.

6. IANA Considerations

The IANA is requested to create an "rpsl-extref-subtype: registry as follows:

          SubType   Reference
          -------   ----------------
          Geofeed   RFC9632

Registration of new SubTypes is by RFC per [RFC8126] Section 4.

7. Acknowledgements

Thanks to the authors of [RFC8805], [RFC9092], and [RFC9632] and the folk they acknowledge from whom ideas and text have been liberally expropriated.

8. References

8.1. Normative References

[I-D.gasser-opsawg-prefix-lengths]
Gasser, O., Bush, R., Candela, M., and R. Housley, "Publishing End-Site Prefix Lengths", Work in Progress, Internet-Draft, draft-gasser-opsawg-prefix-lengths-01, , <https://datatracker.ietf.org/doc/html/draft-gasser-opsawg-prefix-lengths-01>.
[INET6NUM]
RIPE, "Description of the INET6NUM Object", <https://docs.db.ripe.net/RPSL-Object-Types/Descriptions-of-Primary-Objects/#description-of-the-inet6num-object>.
[INETNUM]
RIPE, "Description of the INETNUM Object", <https://docs.db.ripe.net/RPSL-Object-Types/Descriptions-of-Primary-Objects/#description-of-the-inetnum-object>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC2622]
Alaettinoglu, C., Villamizar, C., Gerich, E., Kessens, D., Meyer, D., Bates, T., Karrenberg, D., and M. Terpstra, "Routing Policy Specification Language (RPSL)", RFC 2622, DOI 10.17487/RFC2622, , <https://www.rfc-editor.org/info/rfc2622>.
[RFC8126]
Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, , <https://www.rfc-editor.org/info/rfc8126>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.

8.2. Informative References

[I-D.ietf-regext-rdap-geofeed]
Singh, J. and T. Harrison, "An RDAP Extension for Geofeed Data", Work in Progress, Internet-Draft, draft-ietf-regext-rdap-geofeed-07, , <https://datatracker.ietf.org/doc/html/draft-ietf-regext-rdap-geofeed-07>.
[RFC8805]
Kline, E., Duleba, K., Szamonek, Z., Moser, S., and W. Kumari, "A Format for Self-Published IP Geolocation Feeds", RFC 8805, DOI 10.17487/RFC8805, , <https://www.rfc-editor.org/info/rfc8805>.
[RFC9092]
Bush, R., Candela, M., Kumari, W., and R. Housley, "Finding and Using Geofeed Data", RFC 9092, DOI 10.17487/RFC9092, , <https://www.rfc-editor.org/info/rfc9092>.
[RFC9632]
Bush, R., Candela, M., Kumari, W., and R. Housley, "Finding and Using Geofeed Data", RFC 9632, DOI 10.17487/RFC9632, , <https://www.rfc-editor.org/info/rfc9632>.

Author's Address

Randy Bush
IIJ Research & Arrcus
5147 Crystal Springs
Bainbridge Island, Washington 98110
United States of America