Internet-Draft dns-oops March 2023
Groeneweg, et al. Expires 14 September 2023 [Page]
DNSOP Working Group
Intended Status:
Standards Track
M. Groeneweg
S.W.J. Ubbink
W. Toorop
NLnet Labs

DNS Out Of Protocol Signalling


This document seeks to specify a method for name servers to signal programs outside of the name server software, and which are not necessarily involved with the DNS protocol, about conditions that can arise within the name server. These signals can be used to invoke actions in areas that help provide the DNS service, such as routing.

Currently this document serves as a requirements document to come to a signalling mechanism that will suit the use cases best. Part of that effort is to assemble a list of conditions with potential associated out of DNS protocol actions, as well as inventory and assess existing signalling mechanisms for suitability.

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

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 14 September 2023.

1. Introduction

Operators of name servers can benefit from automatically taking action upon certain conditions in the name server software. Some conditions can be monitored from outside the name server software, but for adequate and immediate action, the name server software can signal itself about the condition immediately when it occurs to invoke action by a listener for these signals.

An example of such a condition is when all zones, from a set served from an anycasted prefix, are loaded and ready to be served, with the associated automatic actions to only announce a prefix route from the point-of-presence where the name server is running, if all zones from the set are ready to be served, and to withdraw the prefix route if one of the zones cannot be served. This way queries for zones will only reach the point-of-presence if the name server software can answer those queries.

Operators of anycasted DNS authoritative services with diverse implementations will benefit from standardizing of the name server signalling, but before coming to a specification for the mechanism, this document will serve to inventorise the already available standardized and non-standardized signalling channels and assess them for usability for out of protocol signalling.

2. Terminology and Definitions

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.

4. Requirements for signalling mechanisms and channels

The following requirements can be distilled from Section 3.

5. Existing signalling mechanisms and channels

What follows is a list of existing signalling mechanisms assessed on their suitability based on the requirements outlined in the previous paragraph.

6. Security and Privacy Considerations

Signalling MUST be performed in an authenticated and private manner.

7. Implementation Status

  • Knot DNS has support for D-Bus notifications (See Section 5.3) for significant server and zone events with the "dbus-event" configuration parameter since version 3.1.6 [Knot-DNS-3.1.6]

8. IANA Considerations

This document has no IANA actions

10. Normative References

Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <>.
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <>.

11. Informative References

Pennington, H., Carlsson, A., Larsson, A., Herzberg, S., McVittie, S., and D. Zeuthen, "D-Bus Specification", , <>.
Arends, R. and M. Larson, "DNS Error Reporting", Work in Progress, Internet-Draft, draft-ietf-dnsop-dns-error-reporting-04, , <>.
CZ.NIC, "Knot DNS - Version 3.1.6", , <>.
Vixie, P., "A Mechanism for Prompt Notification of Zone Changes (DNS NOTIFY)", RFC 1996, DOI 10.17487/RFC1996, , <>.

Appendix A. Implementation Status

Note to the RFC Editor: please remove this entire appendix before publication.

Knot currently uses [D-Bus] for this.

Appendix B. Change History

Note to the RFC Editor: please remove this entire appendix before publication.

  • draft-grubto-dnsop-dns-out-of-protocol-signalling-00

Initial version

Authors' Addresses

Marc Groeneweg
Stichting Internet Domeinregistratie Nederland
Postbus 5022
6802EA Arnhem
Stefan Ubbink
Stichting Internet Domeinregistratie Nederland
Postbus 5022
6802EA Arnhem
Willem Toorop
NLnet Labs
Science Park 400
1098 XH Amsterdam