DNS Resolver

A lightweight DNS resolver implementation in C that performs IPv4 (A) and IPv6 (AAAA) record lookups

Overview

This DNS resolver implements basic DNS query functionality by:

• Building and sending DNS queries to a DNS server (Google DNS - 8.8.8.8)
• Parsing DNS responses including A, AAAA, and CNAME records
• Supporting both IPv4 and IPv6 address resolution

Architecture

Setup Guide

Prerequisites

• GCC compiler
• Make build system
• Linux/Unix environment (for socket programming)

Building the Project

1. Clone the repository

git clone <repository-url>
cd dns-resolver

2. Build the project

make

3. Run the resolver

./bin/dns_resolver <domain-name>

Technical Details

Implementation Notes

• Uses UDP for DNS queries (port 53)
• Maximum packet size: 512 bytes (standard DNS)
• Supports DNS name compression
• Handles multiple answers per query

Usage Example

./bin/dns_resolver www.github.com

Example output:

Response ID: 1234
Answer Count: 2
IPv4 Address: 140.82.121.4
IPv6 Address: 2a00:1450:4009:822::2004