This morning, I read about the DDoS attack on DYN as an outside observer. It was interesting, and scary for what it portends about the future, but it didn't affect me directly.
Then, in the early afternoon, someone in my neighborhood could not access a website that they needed for work. The browser error was less than helpful, but something about resolving DNS. The reports this morning said that things were back to normal, so my initial reaction was to just wait a bit.
By mid-afternoon however, the problem persisted. I tried another web browser, with no luck. Hoping to clear the operating system DNS cache, the computer was rebooted, to no avail.
I was remotely controlling the problematic machine, so at this point I tried to access the website in question on my computer, and it was fine.
The computer with the DNS problem is located one block from me. It connects to the internet using the same ISP that I do. Both machines are running Windows 7. So, why the different outcomes?
I use OpenDNS, the problematic location was using DNS servers from our ISP. So, I modify the router and tell it to always use 220.127.116.11 and 18.104.22.168 as its DNS servers. I've memorized these IP addresses by now.
At first, this changes nothing. Not only does the website failed to load, but the OpenDNS tester page shows that the system is not using OpenDNS. But, a reboot fixes everything. The system picks up the OpenDNS servers and the website now loads fine.
The Defensive Computing lesson in this? Let experts handle what they do best. DNS is not necessarily a core competence for an ISP.