Lately when I try to host a vanilla, bukkit, or modded Minecraft server no one can join. I use the same port, 25565 which is forwarded, and I tried 7777 for Terraria, which a friend connect to Terraria on that port a few days ago, I forwarded long ago, and I know how to port forward in less than 2 minutes without using a guide. I know the IPv4 forwarding and all that, its all done. Simply put, nobody can connect to Minecraft on any port I host, no matter what version it is. I can host other games on these ports just fine and others can connect, my brother can't even connect through 192.168.1.50 (my local ip).
Nobody can connect to my Minecraft servers (but other games like Terraria work)