Quick Tip: Flush the DNS Resolver Cache on Your Computer when Changing DNS Configuration

When migrating a web service or adjusting DNS settings you may come across unexpected behavior of your site long after all errors have been fixed (or so you thought before hitting the Reload button). The hard reality is that in their quest for speed, web browsers try not to make new DNS requests they deem unnecessary. The result is much screaming&steaming from administrators who are in the middle of a job.

Clearing the browser cache won’t work for DNS requests, but you can clear the DNS resolver cache on your OS. On Windows, start the Windows PowerShell (or hit the Windows-R keys for the Run command interface), enter

ipconfig /flushdns

and hit Return.

PS C:\Windows\system32> ipconfig /flushdns
Windows IP Configuration
Successfully flushed the DNS Resolver Cache.

Now you can either restart the browser or reload the page. So long as the DNS changes have sufficiently propagated, your browser should be showing the correct URL.