How do I clear my local DNS Cache?

DNS resolves domain names to IP addresses so people don't have to remember a series of numbers (IP addresses) when navigating to a website. In order to speed up requests and reduce queries to DNS servers, most operating systems cache (temporarily save) DNS lookups locally. If you need to clear that cache (in  order to see changes, this article will walk you through how to do that for these different operating systems: Windows, MacOS, and Linux. The process is generally referred to as clearing or flushing local DNS cache.

Clearing Local DNS Cache in Windows

• Windows 7 and Vista: 
  • Click on the Start Menu 
  • Type cmd in the search box 
  • Right click on cmd in the Programs search result and choose Run as administrator
• Windows 98/NT/2000/XP 
  • Click on the Start Menu 
  • Select run 
  • Type or select cmd to open the command line window

Clearing Local DNS Cache in MacOS

10.4 and below

• Open a Terminal window
• Type this command and hit Return:
• lookupd -flushcache
• Close the Terminal window

10.5 and above

• Open a Terminal window
• Type this command and hit Return:
• dscacheutil -flushcache
• Close the Terminal window

Clearing Local DNS Cache in Linux 

With the various distributions of Linux, you will find that by some run a daemon in the background to manage DNS cache, while others do not. Ubuntu is a good example of a distribution that doesn't run this daemon by default. If you're running Ubuntu and you have not already installed the ncsd daemon, you can install it with this command:

sudo aptitude install nscd

To restart the ncsd deamon in Linux, use this command:

sudo /etc/init.d/networking restart