Track down where packets are being blocked/droped

Question

When I was in China my company's website was blocked for about 24 hours.

I assume it was the "Great Chinese Firewall" but I was wondering if there is anyway that I can find out exactly where a packet or TCP/IP connection gets blocked.

I was able to verify that it wasn't being blocked at our end(I used the local host file to point to the backup server inside of China) or at our servers end (Other people could still connect to both ISPs).

I tried tracert but only port 80 was being redirected. I could ssh into the server without any problems.

The other problem is that most of the routers in china just drop the packets and don't respond to ping etc so you can't find out their IP addresses.

In the future are their any tools that can track down where packets are being blocked?

Answer 1

tcptraceroute

Answer 2

Hello

I have lot's of problems with that firewall. Having my server into EEUU doesn't help. If you need tools to test your site hosted outside from china like you were in China, you can try that page:

http://www.websitepulse.com/help/tools.php

Good luck