So my mysterious DNS problem seems to have magically resolved itself.
Sometime mid-afternoon this past Sunday, my Linux box stoppped resolving URLs. Except for Google, with which it had no problems. However, since my laptop was working fine, it clearly wasn’t an issue with my ISP, and when I checked the network settings on the Linux box, it was clearly pulling the correct addresses for the DNS servers from my router.
So, I spent the next 14 hours or so fiddling with various network settings and rebooting. At some point, a few other sites beside Google started resolving, and at another, I noticed that while I was pinging some random site, my packets were getting filtered. “Great,” I think to myself, “something must have gone wrong with iptables.” I flush iptables. No change. I shut off the firewall. No change.
Then I gave up in frustration.
Wednesday morning, I wake up. As is my habit in the mornings, I turn on the Linux box, log in, and tune in to NPR. It’s a few minutes before I realize that DNS has mysteriously begun working again.
I still have no idea what caused this problem, nor what made it go away. Unless I have a eureka! moment, I’m throwing this one into the “Yeah, computers will do that sometimes…” category.