Last Updated on August 29, 2018 by Dave Farquhar
Early this week, Charter had a major outage affecting most of its customer base. Those who use third-party, non-Charter DNS servers were unaffected.
This is a case where making a performance-related change to your system also makes it more reliable.
I’ve written before about DNS Bench, but let’s talk about how I use that program. There’s not a ton of difference between the 10 or so fastest DNS servers it finds. So what I did was I spread out my DNS settings among three providers. I picked the fastest one, then grabbed the next-fastest one that was run by a different company, and repeated until I had four fast servers from four companies. In my case, I did best with one Level3 server (but not the famous 4.2.2.2), one Qwest server, one NTT Communications server and one Open DNS server.
That’s what to do if you’re after performance. If you’re after security, use Cleanbrowsing.org’s DNS servers.
This spreads out my risk. Now I’m reliant on my ISP only for the wire, which is what they do best. And I’m reliant on four other companies for DNS. It’s extremely unlikely that all three will have a crippling problem at the same time, which makes my connection much more reliable. It’s probably also faster, because DNS lookups add latency. The faster I get the responses to those lookups, the less time my computer sits idle.
If you just upgraded your Internet connection speed but you’re not quite feeling it, chances are your ISP isn’t giving you a very fast DNS. Change it and I’ll bet you’ll be happier. And if you’re thinking about upgrading, change your DNS first and see if that’s enough.
One note: I hadn’t run this program in several years and it found that two of the four DNS servers I picked the last time around were dead. So it’s not a bad idea to re-run the benchmark every so often to ensure you have four live ones. That said, there’s no need to run it every day. That’s excessive.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.
Hi Dave,
Any thoughts on having your DNS not know where you are geographically might slow down data from content delivery networks?
Great question, as some CDNs do use the DNS to determine where you are rather than your address. The DNSs I ended up using almost all turned out to be in Chicago, just like my ISP’s servers anyway, so I haven’t noticed a problem.
If you want to be really safe, look at the actual hostnames of the DNS (which you can sometimes see), and pick servers that are in or near your city.
Do you put the DNS’s sddresses directly in the router and point your PC’s to it or do you put them directly on the individual PC’s?
Excellent question. Put it in the router if you can, but not all routers will let you. If your router won’t take custom DNS settings, by all means put the revised DNBS settings in a desktop PC. I would be more hesitant to hardcode DNS on a laptop or tablet or phone I take elsewhere.
Another instructive article for my Farquhar file. Over the years, I have collected a number of them.
Thanks.