# DNS Style Guide

> [crefft](/index.md) > [Infrastructure](/guides/infrastructure.md) > DNS

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC 2119](https://datatracker.ietf.org/doc/html/rfc2119).

## Quick Reference

| Task           | Tool       | Command                  |
| -------------- | ---------- | ------------------------ |
| Query          | dig        | `dig example.com`        |
| Trace          | dig        | `dig +trace example.com` |
| Check resolver | resolvectl | `resolvectl status`      |

## Overview

TODO: DNS resolver configuration and local DNS services.

## Resolver Configuration

TODO: systemd-resolved, `/etc/resolv.conf` management.

## DNS-over-TLS / DNS-over-HTTPS

TODO: Encrypted DNS configuration.

## Local DNS Server

TODO: Unbound or dnsmasq for local caching/resolution.

## Split-Horizon DNS

TODO: Internal vs external resolution.

## See Also

* [Linux Guide](/guides/infrastructure/os/linux.md) — Base OS configuration
* [Networking Guide](/guides/process.md) — Network fundamentals

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Source version: 2026.10.4. [Source file](https://github.com/agh/crefft/blob/703c8156f7604b464921c851535242202541cfb3/guides/infrastructure/services/dns.md).