---
id: "edns"
kind: "glossary-term"
title: "EDNS"
language: "en"
category: "DNS and technical foundations"
updated: "2026-10-04T14:01:23Z"
canonical: "https://tldlog.com/glossary/edns/"
translations:
  es: "https://tldlog.com/es/glosario/edns/"
  de: "https://tldlog.com/de/glossar/edns/"
  fr: "https://tldlog.com/fr/glossaire/edns/"
  it: "https://tldlog.com/it/glossario/edns/"
  pt-BR: "https://tldlog.com/pt/glossario/edns/"
  ru: "https://tldlog.com/ru/glossariy/edns/"
  zh-Hans: "https://tldlog.com/zh/cihui/edns/"
---

# EDNS

Extension Mechanisms for DNS

An extension to the original DNS protocol that lets DNS messages be larger and carry extra options. DNSSEC depends on it, and it also carries features such as hints about the user's network. Servers and firewalls that handle it badly can cause lookups to fail.

## related terms

- [DNS](https://tldlog.com/glossary/dns/)
- [DNSSEC](https://tldlog.com/glossary/dnssec/)
- [resolver](https://tldlog.com/glossary/resolver/)
- [authoritative server](https://tldlog.com/glossary/authoritative-server/)