SOLVED Difficulty With Minecraft Server

This is yet another "cant create a Minecraft server" post ... I hope someone is in a position to assist. The short version is that the server runs on my computer, but not his.

Both of our computers are hardwired directly to the ASUS RT-AC86U router via ethernet cable. His IP address local to the United States is 192.168.50.166.

These are the settings for port forwarding:

Service Name Minecraft Source IP (blank). Port Range: 2565 Local IP: 192.168.50.166 Port: 25565 TCP : BOTH

When he plays Minecraft on his own computer and directly connects to 192.168.50.166 the connection is established. However when he enters an external IP (obtained via the "Network Map" page of the router's settings), it yields the error:

Failed to connect to the server io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection timed out: no further information

If I try to connect from my computer to 192.168.50.166 I get the exact same error message from Minecraft.

But here's the kicker ... If I run the server on MY computer (192.168.50.48) and alter the Local IP port forward settings according to my preferences, everything works. I can connect to the Minecraft server using either my local IP or with the external IP. Citizensnpcs