DNS Query

In one of the telecommunications courses that I occasionally give, I wanted to show how a web browser “converts” a URL to an Internet address. So I explained how the DNS system woks.

Then one day I thought why not write in my “Forth” a small UDP client that generates DNS queries.

At first I was forced to do everything with IPv4, but in 2016 I changed my ISDN-BRA & DSL access service to a DSL only using VoIP (an “All IP” service). This automatically gave me both an IPv4 and an IPv6 address. So upgraded the UDP client to select between IPv4 and IPv6 access based on the address type of the destination DNS server.

The application supports “A” and “AAAA” record requests, and supports reverse look-ups.

The executable is available via the following link:  Plod DNS Query