Hello! A friend of mine asked me how to check if there were servers running on a local network under a specific port. I wasn’t sure though, and I told him I’d ask here 
I tried a Google search, but only Minecraft stuff comes up.
try and telnet there, if it connects and had rubbish coming back then its active, if you get a connection refused then the port is not open
You can use “-minecraft” to omit results from a google search. Look these little google tricks up, they’re super useful.
Wrote a plugin for that 
-ClaasJG
On windows, you can do:
netstat -np (TCP/UDP) | find "port num"
where port num is the port, and select either TCP or UDP.
Here’s a method to do that
Link? Like, there is nothing worse than googling “GLSL ‘some problem here’” and getting flooded with MC forum threads of 12 year olds talking utter shite.