Using netcat to Test if Minetest Server Network is Okay

I'm busy setting up a demo Minetest server for the Madlab Miners session tomorrow.  The server accepts incoming requests over UDP on port 30000.  I wanted to test my DNS and port-forwarding set up.  I found a really simple example on how to do this using netcat on wikipedia.

On the Minetest server, behind my home router, I  ran the server end:

nc -ul -p 3000

I then logged on to my virtual server on the public internet and connected with:

nc -u minetest.mydomain.com 30000

With both terminals open, whatever I typed into the client end appeared in my server window. The networking is sorted!