i found this site and have tried it ... it is good , and help me for analyzing my internet connection security.

https://grc.com/x/ne.dll?bh0bkyd2
The ShieldsUP! tests depend upon accurately determining your computer's Internet Protocol (IP) address. If your IP address is incorrectly determined the wrong machine will be mistakenly tested. In addition, computers with multiple network connections — like a modem and a network adapter — can have more than one IP address. And machines with only one IP address can have it effectively "hidden" or "masqueraded" if the connection passes through any sort of firewall, proxy server, or other buffering agent.

If you are using a personal firewall product which LOGS contacts by other
systems, you should expect to see entries from this site's probing IP addresses:
204.1.226.224 –thru– 204.1.226.255. Since we own this IP range, these packets
will be from us and will not be any form of malicious intrusion attempt or attack
on your computer. You can use the report of their arrival as handy confirmation
that your intrusion logging systems are operating correctly, but please do not be
concerned with their appearance in your firewall logs. It's expected