Why my own external IP doesn't work for me ?

Question

After setting up static IP and port forwarding, I ran my servlet and replaced "localhost" with my external IP [ got from http://portforward.com/ ], but it failed to get any info from my servlet, why ?

I thought if I use "localhost", the browser just gets the info from my own PC without getting onto the Internet, basically a local trip, and if I use external IP, it sees it as an outside address, go to my ISP, trys to connect to this "external IP", and it just happens to be my own machine, so it talks to my servlet from outside and gets the info, but that doesn't seem the case, how come ?

Answer 1

There is probably a firewall blocking incoming traffic to port 80 (or whatever port you happen to be running your web server on). It's either blocked by a firewall internal to your system or your ISP is blocking it or both. Odds are high that your ISP simply won't allow any incoming traffic on port 80 on their run-of-the-mill internet access plan. They don't want you hosting websites from your house. They would rather you purchase a hosting plan.