How to access Java servlet running on my PC from outside? <p>I used Netbeans6.7 to write a servlet, when it runs, it opens a browser window with this address : <a href="http://localhost:8080/My_App/Test_Servlet" rel="nofollow noreferrer">http://localhost:8080/My_App/Test_Servlet</a>, I replaced the "localhost" with my IP address, now it looks like this : <a href="http://192.???.1.??:8080/My_App/Test_Servlet" rel="nofollow noreferrer">http://192.???.1.??:8080/My_App/Test_Servlet</a>, but I tried to access it from another computer outside my home, it can't read anything, I wonder if I need to change Windows Fire Wall setting to allow outside traffic, it's a Paypal IPN app, so I call Paypal, they said they can't access : <a href="http://192.???.1.??:8080/My_App/Test_Servlet" rel="nofollow noreferrer">http://192.???.1.??:8080/My_App/Test_Servlet</a></p> <p>What on my side should I do to allow traffic from "paypal.com" to access "My_App/Test_Servlet" ?</p> <hr> <p>Partial success ! After I read the articles, set up static IP, port forwaring, I can send one message from Paypal's test IPN page, when I tried to send a second one it couldn't go through, so I stop started my servlet, then I could send another ONE, message, failed again on the 2nd one, why ? Frank</p>