Note: this post is based on experience with Linux.
We’ve all been there - you’re working on a server on your local machine and need to show it to someone else on your local network. You grab your machine’s IP using netstat, ifconfig, or similar and send it over. And… they can’t connect.
If there isn’t an issue with your firewall settings, and you Google the right thing, you may find a StackOverflow post telling you that your server has to bind on 0.