I am writing (already wrote) an application that attempts to connect two or more computers together using Winsock in the Server/Client mode. I wrote to seperate applications one that acts as the Server and the other that acts as the Client. I tested the application out on my own computer (as I only have one pc) and the Client app is able to connect to the Server and send data back and forth. At first I used the 127.0.0.1 IP address, then later changed that to my actual IP address, both worked when running both the Server and Client app on my own PC. Ok, on to the big test. I gave my Client app to someone to run on their home computer and made sure my Server app was up and running. They couldn't connect to my computer. Any idea on what could be going on? Any way to do some kind of ping test in VB between computers? Suggestions?