rootwalk

rootwalk is a tiny DNS resolver I wrote to learn more about how DNS works and to practice writing Go. Read the blog post: https://mostafaahmed.hashnode.dev/series/building-a-dns-resolver-in-go-from-scratch

It's a simple recursive^* resolver using only the Go standard library. It's meant to be used for educational purposes, you probably shouldn't depend on this in production :D.

rootwalk's purpose is to resolve a domain name starting from the root nameservers, it navigates the hierarchy of DNS nameservers and outputs the resolution journey.

^* Recursive resolvers should support result caching by definition, this is a limitation in rootwalk.

Usage

go build
./rootwalk <domain> <root>

# or
go run . <domain> <root>

Where:

• domain is the domain name to be resolved.
• root a value between a - m specifying which root server should be used, defaults to a.

Output Example

Limitations

• No caching
• Limited support for resource record types, only A, AAA and NS atm.