RFC 9609 · BEST CURRENT PRACTICE · 2025
MON · 27 JUL 2026
Initializing a DNS Resolver with Priming Queries
Overview
RFC 9609, “Initializing a DNS Resolver with Priming Queries”, is a Best Current Practice document published in February 2025 by P. Koch, M. Larson, P. Hoffman. It obsoletes RFC 8109. The canonical text is published by the RFC Editor.
Abstract
This document describes the queries that a DNS resolver should emit to initialize its cache. The result is that the resolver gets both a current NS resource record set (RRset) for the root zone and the necessary address information for reaching the root servers.
This document obsoletes RFC 8109.
What “Best Current Practice” means
Documents the IETF community's recommended operational or procedural practice rather than a protocol specification.
Read this RFC
The canonical text of RFC 9609 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
Relationships to other RFCs
Other RFCs from 2025
- RFC 9621 Architecture and Requirements for Transport Services
- RFC 9622 An Abstract Application Programming Interface for Transport Services
- RFC 9623 Implementing Interfaces to Transport Services
- RFC 9626 Video Frame Marking RTP Header Extension
- RFC 9627 The Layer Refresh Request RTCP Feedback Message
- RFC 9628 RTP Payload Format for VP9 Video
- RFC 9664 An EDNS Option to Negotiate Leases on DNS Updates
- RFC 9665 Service Registration Protocol for DNS-Based Service Discovery