This is another "cant' set up a Minecraft server" post ... I hope someone is in a position to assist. The server works on my computer but not on his.
Both of our computers are connected directly to the ASUS RT-AC86U router via ethernet cable. His IP address for local use is 192.168.50.166.
These are the settings for port forwarding:
Service Name: Minecraft Source IP: (blank) Port Range: 25565 Local IP: 192.168.50.166 Local Port: 25565 TCP: BOTH
If he is running Minecraft on his personal computer and directly connects to 192.168.50.166 the connection is established. However, if he enters the external IP (obtained via the "Network Map" page of the router's settings) this will result in the following error message:
Failed to connect to the server io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection timed out: no further information
I get the same error message from Minecraft when I try to connect to 192.168.50.166 from my own computer.
But here's the real kicker ... MINECRAFT SERVERS works when I run the server on my personal computer (192.168.50.48) and modify the Local IP port forward settings in line with the settings. I can connect to the Minecraft server with either my local IP or the external IP.