I forget the term, but some modems have a hard time connecting back to themselves. If you try http://downforeveryoneorjustme.com/
and enter your IP, it should show you as up. I had a bitch of a time figuring this out when I first set up my server.
EDIT: You might need to have a domain name for that website.
I tried that site, and it says my IP looks down from there too. It is possible that this address is my ISP's proxy? Would explain why I don't see my website and this error I got last year
but doesn't explain why it appears down on that site or why it doesn't respond to ping.
No, it's not a serious site. I just created it to test this issue. Plus domain name will also be pointless since I have Dynamic IP address.
-- Wed Dec 01, 2010 5:34 pm --
My suspicions were right. While this computer was still connected, I got a laptop and connected it using another dial-up modem (same ISP) and checking it's IP address using whatismyip.com gives me the same IP address as my first computer. Being a little suspicious, I signed in on gmail with both computers and then checked the computer details. Gmail showed that I was signed in on two different computers both using the same IP. So I guess this IP I'm getting is my ISP's proxy server's.
So I went back to something I noted when I used ipconfig, it was giving me a local/private IP address. This was kind of odd given that I was using a normal dial-up modem and was not connect to any LAN. Out of curiosity I entered that IP on the laptop and my website showed. So I've come to the realisation that my ISP has some sort of private network. Now I logged off the laptop and reconnected using a SIM card of another ISP. My website no longer worked. I reconnect using the SIM card of the first ISP (my main ISP) and the website works.
So is there a way for someone using a different ISP to make a connection with my computer?
The philosopher and mathematician Bertrand Russell was asked, "If a false premise can imply any conclusion, use 1 = 2 to prove you're the Pope!" Russell replied, "The Pope and I are two, so we are one."