Most operating systems are designed to cache DNS records which is generally a good practice as it allows for faster requests to a web site. However, if DNS has recently changed, it may be necessary to flush the cache on your computer in order to retrieve the new DNS records. What this does is remove the local cache from your system and allow you to grab the most recent cache that your ISP is using.

Flushing the DNS records on your computer is very useful when trying to speed up DNS resolution for a newly added or modified domain on your account.

Flushing your DNS cache in Windows

Windows 8 & 10

  1. Click the Windows logo while holding the R key at the same time.
    The run box appears.
  2. In the run box, type cmd and then hit the ‘Enter’ key.
  3. In the command prompt that pops up, enter:
    C:\Users\username> ipconfig /flushdns
    The command runs and returns to the prompt.
  4. Type exit, and then press the ‘Enter’ key to close the window.

When exiting the Windows command prompt, you may see a pop-up box claiming that Windows “…cannot end the program as it may still be running…” – it’s completely safe (and required) to click the End Now button to exit.

Windows 7

  1. Click the Start button, and then type ‘cmd’ in the search bar (where it says ‘search for programs and files’).
  2. In the command prompt that pops up, enter:
    C:\Users\username> ipconfig /flushdns
  3. Press the ‘Enter’ key, and then repeat the process two more times.
  4. Type exit, and then press the ‘Enter’ key to close the window.

Windows Vista

  1. Click the Start button.
  2. In the menu, select ‘All Programs’.
  3. Click Accessories.
  4. Right click on ‘Command Prompt’.
  5. Select the option ‘Run As Administrator’.
  6. In the window that opens, type the following, and then press ‘Enter’:
    C:\Users\username> ipconfig /flushdns
  7. Press the ‘Enter’ key and repeat the process two more times.
  8. Type exit, and then press the ‘Enter’ key to close the window.

If you wish to instead verify what domains and IPs your computer currently has cached, you may use the command ipconfig /displaydns in the steps described above.

Windows XP

  1. Click the Start button and then click Run.
  2. Type in cmd and click OK.
  3. In the window that comes up, enter:
    C:\Users\username> ipconfig /flushdns
  4. Press the ‘Enter’ key and repeat the process two more times.
  5. Type exit, and then press the ‘Enter’ key to close the window.

Flushing your DNS cache in Mac OS X and Linux

Flushing your cache on Mac OS X

The commands to flush cache in OS X are slightly different depending on the version you’re running. First, make sure you’ve opened up your terminal on your computer.

Once opened, run the command below that corresponds to your version of OS X.

OS X 12 (Sierra) and later

macbook$ sudo killall -HUP mDNSResponder;sudo killall mDNSResponderHelper;sudo dscacheutil -flushcache

OS X 11 (El Capitan) and OS X 12 (Sierra)

macbook$ sudo killall -HUP mDNSResponder

Older versions

OS X 10.10 (Yosemite)

Versions 10.10.4+

macbook$ sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder

Versions 10.10.1, 10.10.2, 10.10.3

macbook$ sudo discoveryutil udnsflushcaches

OS X 10.9 (Mavericks)

macbook$ dscacheutil -flushcache; sudo killall -HUP mDNSResponder

OS X 10.7 (Lion) and 10.8 (Mountain Lion)

macbook$ sudo killall -HUP mDNSResponder

OS X 10.5 (Leopard) and 10.6 (Snow Leopard)

macbook$ dscacheutil -flushcache

OS X 10.4 (Tiger)

macbook$ lookupd -flushcache

Flushing your DNS cache in Linux

Most current Linux distributions do not use a DNS resolver cache in the same way that Windows and Mac OS X use. To confirm which particular daemon is installed for your Linux distribution, check the website or its forum pages.

However, a common DNS caching application sometimes used is the Name Service Caching Daemon (nscd). It’s most likely not installed by default so there is no need to flush the cache. But, if you’ve already installed it you can flush the cache by running the following command in a terminal:

[local]$ sudo service nscd restart 

Alternatively, you can try these commands:

[local]$ /etc/rc.d/init.d/nscd stop
[local]$ /etc/rc.d/init.d/nscd start

Further recommendations

  • Make sure that you have closed any browser windows that are open, as they’ll continue to read from the previous cache that was loaded into memory. Then, restart the browser and attempt to view your site. Allow a reasonable amount of time (generally a couple of hours), and then you should be able to see your site online. If not, it’s very likely that your ISP has not updated its DNS cache; it’s not possible to get around this without making some hosts file modifications.
  • Alternatively, you can use a third-party DNS server such as OpenDNS which allows you to manually ask it from their website to update the cache of any domain. In order for this to work, you must manually change your computer’s configuration to use a third-party DNS server; bear in mind that it may not be possible or recommended to use a third-party DNS server in some business environments.
  • Vinkers Hosting support is unable to assist in DNS propagation issues as it is generally the customer’s responsibility.
  • DNS changes may take up to 72 hours to complete – If you notice your site not working after that time, Open Ticket on the Contact Support page.

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