DNS Transport over TCP - Operational Requirements
RFC 9210, “DNS Transport over TCP - Operational Requirements”, is a Best Current Practice document published in March 2022 by J. Kristoff, D. Wessels. It updates RFC 1123, RFC 1536. The canonical text is published by the RFC Editor.
Abstract
This document updates RFCs 1123 and 1536. This document requires the operational practice of permitting DNS messages to be carried over TCP on the Internet as a Best Current Practice. This operational requirement is aligned with the implementation requirements in RFC 7766. The use of TCP includes both DNS over unencrypted TCP as well as over an encrypted TLS session. The document also considers the consequences of this form of DNS communication and the potential operational issues that can arise when this Best Current Practice is not upheld.
What “Best Current Practice” means
Documents the IETF community's recommended operational or procedural practice rather than a protocol specification.
The canonical text of RFC 9210 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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