Thank you for all the help on this!

Once I studied your code and altered mine and got tests working, I found other issues with xinetd and UDP, so, in the long run, I had to send the "Where are you" message on one port, then the server had to reply on a different port. I tried using the same port for the server, but I couldn't open a 2nd socket there using the same port.

While the solution didn't come directly from what you showed me, your code helped me fix what I had wrong there and let to me finding the root issue.

Thanks!