How I Created a Private DNS System That Senior Engineers Couldn't Believe
In this comprehensive tutorial, I build a private DNS server using Unbound and develop a custom C client to interact with it. This setup offers enhanced privacy, performance optimization, and complete control over your DNS infrastructure.
Descubre cómo creé un sistema DNS privado para mejorar la privacidad y el control del acceso a internet.
了解我如何创建一个私人DNS系统，以增强隐私和上网控制。
You’ll see how to structure and parse DNS packets, work with LDNS query types, and handle potential resolution failures gracefully. I also dive into practical aspects like firewall rules, localhost binding, performance tuning in unbound.conf, and testing in isolated networks.
0:00 - Introduction to DNS
Quick overview of DNS and why it's critical for how the internet works.
Descripción general rápida del DNS y por qué es crítico para el funcionamiento de internet.
1:10 - What Are Domain Names and IP Addresses?
Explaining domain names vs IP addresses in simple terms.
Explicación de los nombres de dominio vs direcciones IP en términos simples.
2:00 - DNS is Like a Phone Book
Analogy of DNS functioning like a phone book for the internet.
Analogía de cómo el DNS funciona como una guía telefónica para inter
3:00 - DNS Resolver Explained
How your browser looks up domain names via DNS resolvers.
Cómo tu navegador busca los nombres de dominio a través de los resolutores DNS.
4:00 - Root Name Servers & DNS Hierarchy
Breaking down the DNS hierarchy and root name servers.
Desglosando la jerarquía del DNS y los servidores raíz.
9:00 - Anycast and Root Server Routing
How anycast routes DNS queries to the closest root server.
Cómo Anycast enruta las consultas DNS al servidor raíz más cercano.
9:50 - Registering a Domain & Authoritative Name Servers
How domain registration works and how name servers are assigned.
Cómo funciona el registro de dominios y cómo se asignan los servidores de nombres.
11:10 - Types of DNS Records & Caching
Overview of A, CNAME, MX records and how caching improves performance.
Visión general de los registros A, CNAME, MX y cómo la caché mejora el rendimiento.
13:00 - Full DNS Resolution Flow
Step-by-step DNS lookup from browser to server.
Proceso paso a paso de la búsqueda DNS desde el navegador hasta el servidor.
15:00 - DNS and UDP (Port 53)
Why DNS uses UDP and its role in speeding up queries.
Beneficios de Unbound como un resolutor DNS recursivo, validante y de caché.
19:00 - Building a Private DNS Server in C
Introducing the idea of creating your own DNS server.
Pasos para instalar Unbound, descargar las raíces y habilitar DNSSEC.
20:59 - Why Use Unbound DNS
Benefits of Unbound as a recursive, validating, and caching DNS resolver.
25:46 - Installing and Configuring Unbound
Steps to install Unbound, download root hints, and enable DNSSEC.
Pasos para instalar Unbound, descargar las raíces y habilitar DNSSEC.
28:13 - Unbound Configuration for Privacy
Setting Unbound to localhost and tuning performance settings.
Configurar Unbound en localhost y ajustar las configuraciones de rendimiento.
33:25 - Writing a DNS Client in C
Overview of the C program using libunbound to query the DNS server.
Descripción general del programa en C utilizando libunbound para consultar el servidor DNS.
37:37 - Memory Management & Low-level DNS Query Handling
Handling memory and query logic in the C program.
Cómo manejar la memoria y la lógica de consultas en el programa en C.
49:00 - Running DNS in Isolated Environments
How to use Docker, VM, or offline setups for testing your DNS server.
Cómo usar Docker, VM o configuraciones fuera de línea para probar tu servidor DNS.
54:00 - Custom Use Cases: Privacy, Ad Blocking, DNS over TLS
Extending your DNS server with advanced features and real-world use cases.
Extender tu servidor DNS con características avanzadas y casos de uso del mundo real.
56:47 - Final Thoughts and Outro
Recap, benefits of learning DNS deeply, and closing thoughts.
Resumen, beneficios de aprender DNS a fondo y pensamientos finales.
✅ GitHub Gist (code + config):
https://gist.github.com/anglerfishlyy...
Unbound DNS Resolver Documentation
https://nlnetlabs.nl/documentation/un...
ldns Library Reference
https://www.nlnetlabs.nl/projects/ldns/
DNS Protocol RFC 1035 (The foundational DNS specification)
https://datatracker.ietf.org/doc/html...
PowerDNS Recursor Source Code (For alternative implementation ideas)
https://github.com/PowerDNS/pdns
ldns Library GitHub Repository
https://github.com/NLnetLabs/ldns
Unbound DNS GitHub Repository
https://github.com/NLnetLabs/unbound
Wanna hire me, upwork link is in the bio.
This project is inspired by the systems-level content of channels like Fireship, Low Level Learning, and ThePrimeagen.
#dns #NetworkProgramming #CProgramming #Cybersecurity #Programming #SoftwareEngineering #NetworkSecurity #PrivacyTools