For the past two weeks I have been unable to reach two sites from my home PC, www.dofasco.ca and www.hamiltonspectator.com.

At first I thought it had something to do with both of them being in hamilton, until a quick peek at this site (if you can read Italian or at least make out what it means) shows that the Spec is hosted out of Montreal. So much for that idea.

A lengthy conference with my ISP showed that all traffic for all customers goes through their routers (ie: not Bell’s router), and other customers had no problems. End result: not their problem.

I could resolve the name, but not ping, FTP or use any other protocol that worked two weeks ago. My firewall (running on the modem) is configured to block anything from external, but allow everything from internal. I even reset it completely to no avail.

Then I plugged a laptop into the modem, and wouldn’t you know it, the laptop had no trouble at all. PC was furiously plugged back in, and I ran a network sniffer on my PC. Hey look, the PC was doing ARP requests, trying to find someone, anyone, who would answer to the correctly resolved IP addresses in question. After a bit of fiddling I added two static ARP entries… and now everything works fine.

This has by far been the most bizarre problem I’ve run across, and I still don’t have an explanation as to why this happened. Any ideas?