Internet-Draft Deprecation Of BGP OPEN Error subcodes October 2022
Snijders Expires 15 April 2023 [Page]
Intended Status:
Standards Track
J. Snijders

Deprecation of BGP OPEN Message Error subcodes 8, 9, and 10.


This document requests IANA to mark BGP OPEN Message Error subcodes 8, 9, and 10 as "deprecated".

Status of This Memo

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

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at

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This Internet-Draft will expire on 15 April 2023.

1. Introduction

It has been discovered that certain BGP OPEN Message Error subcodes have been used in BGP implementations which have been deployed in the wild while not being assigned by the IANA for such usage. Unregistered usage of BGP OPEN Message Error subcodes can lead to increased difficulty when troubleshooting why BGP sessions are torn down.

The use of these unregistered values was noticed when the concept of Route Leak Prevention and Detection using Roles in UPDATE and OPEN Messages [RFC9234] was initially assigned value 8 by IANA. It was subsequently discovered that a widely-deployed BGP-4 [RFC4271] implementation had released code which used BGP OPEN Message Error Subcode 8. As a workaround, a new Early IANA Allocation is to be requested.

The squatting of values 8, 9, and 10 has been confirmed by the involved vendors or through source code review.

2. IANA Considerations

Per this document, IANA is requested to mark values 8, 9, and 10 as "deprecated" in the "OPEN Message Error subcodes" registry under the "Border Gateway Protocol (BGP) Parameters" group. The marking "deprecated" meaning "use is not recommended" ([RFC8126]).

3. Security Considerations

There are no meaningful security consequences arising from this registry update.

4. Informative References

Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, , <>.
Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, , <>.
Azimov, A., Bogomazov, E., Bush, R., Patel, K., and K. Sriram, "Route Leak Prevention and Detection Using Roles in UPDATE and OPEN Messages", RFC 9234, DOI 10.17487/RFC9234, , <>.

Author's Address

Job Snijders