Last Updated on August 21, 2016 by Dave Farquhar
One of the most maddening things that can happen when you’re using a computer is that a web site you visit routinely quits working. Your Internet connection appears to be fine, but suddenly, for some reason, you can’t go to the site you were just using. Try to go to another site you haven’t visited in a while, and it’s fine. But whatever site you were using a minute ago doesn’t work anymore. The site becomes accessible again immediately after you reboot, but that’s a really big hassle.
There’s a much less drastic fix. It’s easy too, but non-obvious.
A grizzled network engineer trick
Open a command prompt and type the following command: ipconfig /flushdns then hit enter.
Windows caches the addresses of web sites you visit, but when your Internet connection becomes unavailable for a split second, sometimes it will cache a non-existent address. So even when your Internet connection comes back, whatever site you were trying to visit remains unavailable, because the computer remembers it being unavailable and is too lazy to check and see if it’s back.
Any time I have problems with my Internet connection, this command is the first thing I do. Even before I check to make sure my modem is online. I just do it from a command prompt, because I always have a command prompt open. But if you don’t, you might like a different way to run it.
How to create a shortcut that runs ipconfig /flushdns
Right-click on your desktop and select New, Shortcut. Type c:\windows\System32\ipconfig.
Now you can drag the icon to your Start menu. To keep it readily accessible at all times, you can drag it into the pinned items, immediately above or below your web browser and e-mail.
In the event that ipconfig /flushdns fails, here’s a more drastic fix that almost always will.
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.
Thank you!
I’m still on prehistoric dial-up, and there are certain periods of the day when this problem is extremely common. Having to keep re-trying, which means re-dialing, gets a good deal more expensive than I’m comfortable with. However, my ISP and my telco are one-and-the-same, so they’ve got no incentive to fix it – quite the opposite, I sometimes suspect. Not having to re-dial several times to re-establish a connection that should never have gone bad is definitely going to be a GOOD THING.