trying to visit a website. In order the speed up this process and reduce the traffic on the DNS servers, most computer operating systems will store or cache DNS lookups on your computer locally. At times, you may need to clear the cache to see changes . In this tutorial, we'll show you how to clear the DNS cache for the major operating systems on the market. Typically, this process is referred to as clearing or flushing the local DNS cache.
Flushing Local DNS Cache in Windows
Open the command line window, and depending on your version of Windows, this can be done in one of the following ways:
- Windows 7 and Vista:
- Click on the Start Menu
- Type cmd in the search box
- Right click on cmd in the programs search results 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
Once the command line window is open type the following command at the prompt and hit enter
ipconfig /flushdns
After the flushdns is cpmpleted, type exit to close the command line window.
Flushing Local DNS Cache in Mac OS X
OS X 10.10
- Open a Terminal window
- Type this command and hit return
sudo discoveryutil mdnsflushcache
As of version 10.10.4, Apple has changed the command to the following:
sudo killall -HUP mDNSResponder
- Close the terminal window
OS X 10.7 - 10.9
- Open a Terminal window
- Type this command and hit return
sudo killall -HUP mDNSResponder
- Close the terminal window
OS X 10.6 and below
- Open a Terminal window
- Type this command and hit return
sudo dscacheutil -flushcache
- Close the terminal window
Flushing 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
