Specifically, I was running a node.js application on port 6969 which I thought was strictly local. I discovered this was not the case when I ran
nmap <myip> from a different computer and found that it showed port 6969 open as a service called
acmsoda. This is strange in the first place, since acmsoda seems to be a torrenting related service, of which I don't have any relevant software installed. What's weirder though, is that I changed the port of my node.js application to 6968 and it now no longer shows up remotely using nmap (although it is still remotely accessible).
Is there something about port 6969 on OSX that makes it unfiltered? Should I be weary of using this port?