Troubleshooting - "Page cannot be displayed" or "xyz.com could not be found"

I was in a predicament a while ago. I first noticed the symptoms when my bittorrent client (BitComet) could not connect to any peers other than for those in the DHT network.

When I tried browsing the internet, I'd get "Page cannot be displayed" intermitently, sometimes a refresh will do the trick, or refreshing until internet explorer says "Opening xyz..."

This went on for a good part of 5 hours before I found the solution. At first I thought it was problem with the bittorrent client since I was under a NATted corporate firewall. So I got myself BitSpirit, hoping that it could somehow punch through the security. No go.

Next I looked at transparent http proxy tunneling. These sevices will route all your traffic through your http proxy, usually at port 80 or 8080. There was HTTP-tunnel, but unfortunately even at just the Test connection step, it could not connect to its own servers. Fat chance.

I then browsed for anonymous proxy lists and found some hand full ranging from Croatia to India, from the Philippines to Mexico. I then filtered the list using batch ping and tracerts to get rid of the ones that have been taken down.

I still had about around 20 proxies left. I then *manually* changed the internet explorer settings and restarted the browser for each of these. Though I could browse the internet, it still had the same problem, intermittently showing the "Page cannot be displayed" every so often. It was really getting annoying.

Finally as a last resort, I tried resetting the TCP settings by:

netsh int ip reset c:\resetlog.txt

and then running:

http://downloads.subratam.org/WinsockFix.zip

After a short reboot, viola! I was back on track again. =D

Everything worked perfectly after that. No more browser page reloads, and the peers connected smoothly.

It just left me wondering how it happened in the first place... hmnhh...