I posted this on the Minecraft Forums, but nobody has responded to it. Hoping I can get help here.
Long story short, I used to host a few small minecraft servers. I didn't for a few months, and was going to fire them up again. Nothing has changed since I hosted them previously, except that I got a new router. I've tried making a new server as well, and am running into the same issue of Minecraft not being able to detect the server.
I have port 25565 (which is also what's in my server.properties) open on 192.168.1.2, which is the internet address for my computer. When I open minecraft with the server running, it can't find the server.
Notably, when I ping that port/address on http://www.yougetsignal.com/tools/open-ports, my server log even SHOWS it's getting pinged. So obviously the connection is working.
Right now I am testing with server and client 1.5.1 (since thats what I was on last time it worked) however the problem is still present in 1.5.2.
Also, when I previously made the original post on the other forums... My server log would even show my computer pinging the server (but still couldnt find it). This behavior has since disappeared.