This is a starting point for Java solutions to the "Build Your Own DNS server" Challenge.

I built a DNS server that's capable of parsing and creating DNS packets, responding to DNS queries, handling various record types and doing recursive resolve. Along the way I learnt about the DNS protocol, DNS packet format, root servers, authoritative servers, forwarding servers, various record types (A, AAAA, CNAME, etc) and more.

Note: If you're viewing this repo on GitHub, head over to codecrafters.io to try the challenge.

Download the source code

Run the below command on your terminal to clone the repository locally on your machine.

git clone https://github.com/10adnan75/dns-server.git

Fork or create your own repository on Github

Run the below commmands on your terminal to initialize a repository.

git init
git remote add origin <your-repository-url>
git add .
git commit -am "your-commit-message" # any msg
git push origin master

Run locally on your machine

The entry point for your your_program.sh implementation is in src/main/java/Main.java.

Server: Open a terminal, and compile and run your java code using the below commands:

cd /dns-server
/target/classes Main --resolver <address>

Client: Open another terminal, run the following command:

dig @127.0.0.1 -p 2053 +noedns <SLD.domain@TLD>

Testing & beyond

Note: This section is for testing and beyond.

1. Ensure you have mvn installed locally
2. Run ./your_program.sh to run your program, which is implemented in src/main/java/Main.java.
3. Commit your changes and run git push origin master to push your code to Github. Test output will be streamed to your terminal.

Output

Server

Client