So I'm in the last steps of setting up a server for my friends and I using a modified Tekkit Legends pack. This is not the first server I've made, and I can confirm my ports are properly forwarded via my router (port 25565 reads as open via external services when the server is on, and closed when it's off) and that all my server settings are optimal (server-ip is blank, server-port is 25565, online-mode is true in server.properties). However, the server still does not show up and can't be connected to via my external IP. The only remaining thing I can't confirm is that Windows Firewall is letting connections through. I have custom rules that allow port 25565 inbound and outbound via TCP and UDP, but the server is still inaccessible. What gives? I'm running windows 10, is there some background service blocking the connection?
Well I grabbed one of my players and asked him to try connecting. Turns out it was working fine all along! See, in the previous servers I've set up, connecting to a server I was running on the same machine using the external IP was no problem, it just worked. Thank you for your help, this is definitely going in my basic procedure in the future.