Status of zytrax.com "DNS for Rocket Scientists" website

[Carsten Strotmann]

Hi,

does anyone know about the status of the zytrax.com website and the 
excellent "DNS for Rocket Scientists" guide?

The webpage first had a x509 certificate error (expired) in December 
2020 and now the web server is unreachable.

I (and colleagues) have tried to reach Ron Aitchison by mail and other 
communication means, but no success.

Greetings

Carsten