STD 75

RFC 6891

Extension Mechanisms for DNS (EDNS(0)), April 2013

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RFC 2671, RFC 2673
J. Damas
M. Graff
P. Vixie
dnsext (int)

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The Domain Name System's wire protocol includes a number of fixed fields whose range has been or soon will be exhausted and does not allow requestors to advertise their capabilities to responders. This document describes backward-compatible mechanisms for allowing the protocol to grow.

This document updates the Extension Mechanisms for DNS (EDNS(0)) specification (and obsoletes RFC 2671) based on feedback from deployment experience in several implementations. It also obsoletes RFC 2673 ("Binary Labels in the Domain Name System") and adds considerations on the use of extended labels in the DNS.

For the definition of Status, see RFC 2026.

For the definition of Stream, see RFC 8729.

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