dns_server

A small recursive DNS server written in Rust. It listens on UDP 0.0.0.0:2053, walks the DNS hierarchy starting from the root server at 198.41.0.4, and returns answers for common record types (A, AAAA, NS, CNAME, MX).

Build

• Install Rust (edition 2024 is used).
• From the project root, run:
  • cargo build

Run

• Start the server:
  • cargo run
• The process logs incoming questions and the records returned.

Try it

• From another terminal, ask for a record with dig:
  • dig @127.0.0.1 -p 2053 example.com A
  • Swap A for AAAA, NS, CNAME, or MX to try other types.

Notes

• UDP only; no TCP fallback.
• No caching; each query is resolved from the root.
• Response size is limited to 512 bytes.
• No DNSSEC handling.