DNS-Forwarder

A simple DNS Forwarder that can resolve the IP address for a host either from it’s local cache, or by forwarding the request to an authoritative nameserver.

Table of Contents

• DNS Forwarder
• Introduction
• Installation
• Usage

Introduction

The DNS Forwarder is a lightweight utility designed to streamline DNS resolution by efficiently retrieving IP addresses for hosts. It operates as a simple DNS forwarding service, utilizing a local cache for quick lookups and seamlessly forwarding unresolved queries to authoritative nameservers. This project is based on John Crickett's coding challenge #44.

Installation

This project can be easily deployed using Docker. Follow the steps below to install and run the project using Docker:

Prerequisites

Before you begin, ensure that you have Docker installed on your machine. If you haven't installed Docker yet, you can download and install it from the official Docker website.

Installation Steps

1. Clone the Repository: Clone the project repository to your local machine using the following command:

    git clone https://github.com/AkshayViru/dns-forwarder.git
   

2. Navigate to the Project Directory: Change into the project directory:

    cd dns-forwarder
   

3. Build the Docker Image: Build the Docker image using the provided Dockerfile. Run the following command in the project directory:

    docker build -t dns-forwarder .
   

4. Run the Docker Container: Once the Docker image is built successfully, you can run the Docker container using the following command:

    docker run -d -p 1053:1053/udp dns-forwarder
   

Usage

• Send a request to DNS Forwarder and you should see a response like so:

    % dig @0.0.0.0 -p 1053 www.google.com
  
    ; <<>> DiG 9.10.6 <<>> @127.0.0.1 -p 1053 www.google.com
    ; (1 server found)
    ;; global options: +cmd
    ;; Got answer:
    ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43712
    ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
    
    ;; OPT PSEUDOSECTION:
    ; EDNS: version: 0, flags:; udp: 512
    ;; QUESTION SECTION:
    ;www.google.com.                        IN      A
    
    ;; ANSWER SECTION:
    www.google.com.         118     IN      A       142.250.179.228
    
    ;; Query time: 11 msec
    ;; SERVER: 127.0.0.1#1053(127.0.0.1)
    ;; WHEN: Wed Jan 10 18:09:54 GMT 2024
    ;; MSG SIZE  rcvd: 59
  

• Retrying a request before the time-to-live (TTL) provided by authoritative nameserver can offer faster response retrieval, benefiting from the cached response in the DNS Forwarder.

• To use any port other than 1053, update PORT value in the dockerfile and in the 4th step of Installation instructions above.