I guess I wasn't clear, if "Next time you guess you'll know."

"Working" means it must still exhibit the problem. All I got was "Undefined subroutine &main::get_config called". That's not the problem you asked us to solve.

"Minimal" means that anything everything that doesn't affect the error should be removed. If anything else were to be removed, the code would no longer exhibit the problem.

I didn't "make up" anything. I just stripped out the config code and the IP socket code. (Update: Oops, I did switch from the indirect method call syntax to the direct one, because there are problems associated with the indirect method call syntax.) Since the remaining code still give the error you are trying to fix, that means I eliminated your config code and your IP code as possible sources of the problem. If it had solved the problem, that means the error was in the config code or the IP code.

What OS and Perl are you using? Maybe they don't support features you require.