• Flush DNS

    Modern browsers, OS and DNS clients stores cache of IP addresses and other DNS information automatically. When a computer visits a website for the first time, it stores the website's DNS information in the cache. The next time the computer visits a website, it looks in the cache to see if the web site's information is present to use. An old version of a site opens if the website's DNS information has changed since the computer's last visit. Flushing the cache removes all the data stored in the cache, forcing the computer to find the new DNS information for the website. Usually, it is done to speed up the process and minimize requests for same hostnames. When IP addresses are changed, or bad results are cached, its necessary to clear the DNS cache. DNS cache can be cleared via command line or from browsers also. Steps to flush DNS Cache for major operating systems and browsers are as below.


    Windows 8/ Windows 8.1 DNS Flush

    Because of the system security policies run cmd as administrator user and follow below steps to flush DNS cache.


    1. Press Windows key + X and select the Command Prompt (Admin) option from the Power User menu.
    2. Type in the command ipconfig /flushdns


    Windows Vista / Windows 7 Flush DNS

    To flush DNS on an upgraded version of Windows is almost as easy as it is in the previous versions but due to Microsofts upgraded security system requirements, you must run the command prompt with administrator privileges.


    1. To flush DNS through the command prompt, navigate as shown (Start > All Programs > Accessories > Command Prompt)
    2. to have administrator privileges, you must do right click on the command prompt application and choose "Run as Administrator."
    3. Type in the command ipconfig /flushdns


    Short-cut

    Type in cmd into the Windows Vista / Windows 7 start menu search field and then right click on the cmd.exe result instead of navigating through the various sub-menus.


    Windows 98/NT/2000/XP Flush DNS

    Given below steps will help you to clear your windows DNS cache.


    1. To access command prompt (Start > Run > ).
    2. Type the cmd and hit Enter
    3. In the CMD window that you just opened, Type in the command ipconfig /flushdns


    Mac OS X Flush DNS

    Flushing the DNS in Mac OS X is an easy process, but the steps taken will depend on which version of OS X is running as your operating system.

    Mountain Lion or Lion

    If you are using Mac OS X 10.7 or 10.8, as your operating system, you need to do the following:

    1. Access the command terminal.
    2. Run the following command in the terminal sudo killall -HUP mDNSResponder

    Snow Leopard

    If you are using Mac OS X 10.6, as your operating system, you need to do the following:

    1. Open up a command terminal.
    2. Run the command in the terminal dscacheutil -flushcache

    Leopard and below

    If you are using Mac OS X 10.5.1 or below as your operating system, you need to do the following:

    1. Open a command terminal.
    2. Run the command in the terminal lookupd -flushcache

    Linux Flush DNS

    If you are running the nscd Name Service Cache Daemon then you will need to do the following.

    1. Open up a command terminal (either as root or run step 2 with sudo )
    2. Run the command in the terminal /etc/init.d/nscd restart