WHO IS TO BLAME FOR THIS OUTRAGE? (Network error: XXX)

This is a very basic set of troubleshooting steps for remote TCP services, which include a couple of tests to determine the important thing in these situations...

"WHO IS TO BLAME FOR THIS OUTRAGE?"

So its not working.

What is not working? Just some random TCP service on the network, MySQL-port 3306, MS SQL 1433, tomcat 8080, apache 80, you can check the IANA database of registered port assignments for 57333 million other examples.

(in fact this has run a bit long, so this is just Part 1 - the common error messages, the payoff, ie who to blame has got pushed back to part 2, or 3...)