Forums/OpenDNS Community/Troubleshooting and Support

Clearing the DNS Cache on Computers and Web Browsers

Chris Frost
posted this on February 1, 2014, 12:48

The following table provides instructions for clearing the DNS cache on computers and servers. The commands need to be run at the command prompt with administrator privileges.

Please add any additions, corrections, updates or suggestions to the comments on this article to better help the community.

 

Windows_XP_2001.jpg

Windows 7 and Earlier

 

  1. Click the Start Menu
  2. Go to All Programs
  3. Choose Accessories and right-click Command Prompt
  4. Choose Run as Administrator

     Run the following command in the command line and hit enter

ipconfig /flushdns
Windows_logo_-_2012.png

Windows 8

 

  1. Press the Windows Key or hover your mouse over the bottom left corner and click the Windows Icon
  2. Begin typing Command Prompt
  3. Right-click the application and select Run as Administrator

     Run the following command in the command line and hit enter

ipconfig /flushdns
104.png

OS X 10.4 TIGER

 

  1. Click the Terminal icon in the dock or in Finder under Application/Utilities/Terminal

     Run the following command in the command line and hit enter

lookupd -flushcache
leopard_os_x.gif

OS X 10.5 and 10.6 LEOPARD

 

  1. Click the Terminal icon in the dock or in Finder under Application/Utilities/Terminal

     Run the following command in the command line and hit enter

dscacheutil -flushcache
OS-X-Lion-Logo.jpg

OS X 10.7 and 10.8 Lion

 

  1. Click the Terminal icon in the dock or in Finder under Application/Utilities/Terminal
sudo killall -HUP mDNSResponder
apple-logo-600px-304.jpg

OS X 10.9

 

  1. Click the Terminal icon in the dock or in Finder under Application/Utilities/Terminal
dscacheutil -flushcache;sudo killall -HUP mDNSResponder
apple-logo-600px-304.jpg

OS X 10.10 Yosemite

 

  1. Click the Terminal icon in the dock or in Finder under Application/Utilities/Terminal
sudo discoveryutil mdnsflushcache;sudo discoveryutil udnsflushcaches;say flushed
871px-Linux_logo.png

Linux (most distributions)

 

  1. Open a terminal window (gnome-terminal, konsole, xterm, etc)
sudo /etc/init.d/nscd restart
   or
sudo /etc/init.d/nscd restart
ubuntu-logo1.gif

Ubuntu Linux

 

  1. Open a terminal window

     Run the following command in the command line and hit enter

 sudo service network-manager restart

Clearing the DNS Cache on Browsers

 

 If you have recently set up your filtering, or just changed a setting, a cache clear may be necessary before you see your filtering take effect. Please follow the below instructions and also the steps at the Computer DNS Cache clearing instructions.

The following table provides instructions for clearing the DNS cache within common Internet browsers.

Browser

 

Steps to clear the DNS Cache

 

Internet Explorer  8 and above (Windows)

 

Go to the History menu, select Delete Browsing History, check all boxes (except passwords, if desired) and click Delete.

 

Mozilla Firefox (Windows)

 

Click on Firefox at the top left of your browser, go to the History menu, select Clear Recent History and check all boxes. Under Time range to clear select Everything (except passwords, if desired) and click Clear Now.

 

Apple Safari (Windows)

 

Expand the Cog Icon in the upper right corner and select Reset Safari. Check all boxes and click Reset.

 

Apple Safari (Windows)

 

Go to the Safari menu, select Reset Safari, check all boxes and click Reset.

 

Google Chrome (Windows)

 

Expand the Wrench Icon in the upper right corner and select History and check all boxes. Under Clear data for this time period, select Everything(except passwords, if desired) and click Clear Browsing Data.

 

Google Chrome (Mac) Under Go to the Chrome menu, select Clear Browsing Data and check all boxes (except passwords, if desired). Under Clear data for this time period, select Everything and click Clear Browsing Data.

 

 

 

 

Comments

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vasinc

Didn't seem to work with Mavricks

February 11, 2014, 06:20
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Kristy Patullo
OpenDNS

Thanks for pointing this out.  The latest version of OS X requires the following commands entered in the Terminal in order to flush the DNS cache:

Enter this command:

dscacheutil -flushcache

Then, to reload DNS type this command:

sudo killall -HUP mDNSResponder
February 11, 2014, 08:48
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island123

Didn't seem to work for me with Mavricks also. Did both commands - it asks for a password in terminal

February 13, 2014, 12:04
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Kristy Patullo
OpenDNS

These commands must require administrative authority to run in terminal on your device.  If you are the administrator of your device enter your keychain password.

February 13, 2014, 12:36
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sryokan

dscacheutil -flushcache;sudo killall -HUP mDNSResponder

same as above but in a single string. 

February 18, 2014, 22:34
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icevirg

This part worked just like your instructions & illustrations indicated!! Now to purge my web browser caches. ;)

February 19, 2014, 13:34
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drrdm

I tried the instructions for Mavericks, but when I get to the password request, the terminal won't respond to the keyboard. I type, but nothing shows, so I can't enter my password.

February 22, 2014, 09:49
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rotblitz

What do the Apple support forums say?  Here are the OpenDNS experts, the Apple experts are somewhere else.

February 23, 2014, 05:58
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paul

When you type, the Mac will see your password, even if you can't. Trust that you can type the correct password and hit enter. Voila.

February 24, 2014, 19:49
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patechmanager

This advice needs major revisions

a) add support for Mac os 10.9

b) Delete the picture

c) Add text examples that can copy and paste

ps: THe picture does not allow me to copy/paste into a terminal.  

 

February 26, 2014, 16:09
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skylar_l

@island123 and drrdm:

Mac OS X and I'm pretty sure Linux requires you to enter in the administrator (or Keychain) password to perform this action. When you type in the password, it will NOT show any dots or text (This is a security measure). Just press Enter/Return once you have finished typing it.

As for Windows Vista, Seven, and Eight: After typing cmd into the search, you need to right click on cmd.exe and click "Run as Administrator"; Then type in "ipconfig /flushdns".

February 26, 2014, 19:36
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Matt Prytuluk
OpenDNS

Hi all,

Thanks for the feedback, and apologies for the delay in the corrections/updates.  The feedback is greatly appreciated, please let us continue to update this as required, as new operating systems or instructions become available.

Best regards,

Matt

March 14, 2014, 09:32
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patechmanager

Fixed.  Thanks for adding text we can copy and paste.   And thanks for adding OSX 9 command.   Just needed this again today.   It' so easy to google this, then bingo, copy and paste to flush.        We have a lot of educational apps that only work after flushing the DNS cache.   

March 14, 2014, 11:30
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bcrouch5

My windows isn't working I input - ipconfig /flushdns

and I get the following error message: The reqested operation requires elevation.

What does that mean and what's the next step?

Thanks

bcrouch5

 

March 29, 2014, 12:38
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skylar_l

@bcrouch- Quite literally three comments up, I explained that you have to right click on cmd, then click "Run as administrator".

March 29, 2014, 13:30
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jtorres

I take it Windows Server 2012 is very similar to 2008, but is there anything additional that would need to happen after the forwarders are entered and the ipconfig /flushdns is ran as an admin on the server?

April 1, 2014, 10:22
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rotblitz

No.

April 1, 2014, 23:23
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ramirgl

I'm having the same problem.  Running Vista.  After typing cmd in the run menu, the C:\Windows\system32\cmd.exe dialogue box pops up.  I enter ipconfig/flushdns and am told that "the requested operation requires elevation".  I have tried to right click as was suggested above to select "Run as administrator", but that is not an option when I right-click.  I only have the dialogue box properties if I click on the box heading, or "Mark, Paste, Select All, Scroll, Find" if I right click in the box field.  Any advice would be greatly appreciated.  Thanks.

April 2, 2014, 08:46
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rotblitz

Start > All Programs > Accessories > Right-click "Command Prompt" > Run as Administrator

(Hoping you don't drive a car with the same skill level for cars. :shocked:)

April 2, 2014, 09:02
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patechmanager

This is my attempt to help bcrouch5 and ramirgl.

The failure with "ipconfig" command on your computer is due to security restrictions on your account or computer.  Most likely your computer was purchased and setup by another person with the privileges to maintain the computer.   This is a protection mechanism to keep novice users from  harming their own computer.  

Your windows computer has several user accounts and you are using an account that does not have the security privileges that are needed to run "ipconfig".      Right click "run as admin" will fail until you logout and logon as an admin user. 

solutions:  

a) avoid using ipconfig and istead  reboot.   Just reboot the phone, ipad, tablet, or computer.  In most cases a full restart will flush the DNS cache.   

b) call a friend who knows windows and networking and can help you and explain this

b) Use another account on your computer and then use ipconfig.   Go to your control panel , then users, and you should see 2 or more user accounts.    

Do not use an account with "standard user"

Do use an account with "administrator"

note: using ipconfig is a job that requires a lot of networking background and knowledge.   The 2nd sentence written by Chris Frost states that you need administrator privileges.      What is also implied is that you need administrator skills and training.  

April 2, 2014, 09:35
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notfalse

For Ubuntu it is: sudo service network-manager restart

April 3, 2014, 13:49
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philp777

Ok, so I reset the setting for DNS and then went to the Start menu and entered "cmd" and then pressed "Enter" and a black window came up and a chill went down my spine. 

Presumably that black window is the Command Prompt/Terminal where it tells you things about Miccrosoft and says "C:UsersPhillip>"

So I typed in "ipconfig /flushdns" and it thought about that and said "The requested Operation Requires Elevation" so I took my PC onto the roof but it made no difference!

Have I gone wrong somewhere?

Please advise,

Phil

April 10, 2014, 07:28
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rotblitz

"went to the Start menu and entered "cmd" and then pressed "Enter""

This was wrong.  Proceed as I have described in my previous answer to get to the elevated prompt.

Better copying & pasting it to here for your convenience:

Start > All Programs > Accessories > Right-click "Command Prompt" > Select "Run as Administrator"

April 10, 2014, 10:06
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mixelixx

@notfalse - Thanks for the Ubuntu info. Works for Lubuntu.

April 15, 2014, 11:52
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armpit44

Anyone know how to flush Safari?

April 18, 2014, 19:19
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rotblitz

You flush the website cache from the tools icon.

April 19, 2014, 05:58
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rotblitz
April 19, 2014, 06:00
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sonu.javaid

Hello Helpers,

 

I need help. I just signed today to OpenDns from London UK. I am not very computer intelligent, well I guess I classify myself as a bimbo when it comes to computers and technology. Anyway I followed all instructions provided, now having reached this step I am confused to what happens now. 


Go to Start Menu > Run > Type "cmd" > press Enter/Return

 What am I do after this stage. I black box appears then what?? Please advice.

Thank you very much please support. 

April 24, 2014, 03:17
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rotblitz

"Go to Start Menu > Run > Type "cmd" > press Enter/Return"

This was wrong.  Copying from above again:

Start > All Programs > Accessories > Right-click "Command Prompt" > Select "Run as Administrator"

"What am I do after this stage. I black box appears then what??"

ipconfig /flushdns                                                (then press Enter)

April 24, 2014, 07:10
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vivispix

Recently I went onto Youtube and just read some of the notes people leave. As here I read what others had to say and found that, gee, that was me not long ago. Especially about driving a car. Well I'm getting old but never had a speeding ticket. Been taking computer since 1987 but manage to brick most and have to begin again. I hope this resolves my DNS issues as I've just installed a new router. I am grateful you are here and hope your patience holds out till I've got it right. Thanks for being here. Vivi 

April 26, 2014, 13:21
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marcusbrittanicus

I am on Mavericks, none of this works at all. Can we have SIMPLE step by step guide?

For example, do i enter my password and code then press enter?

Do I enter password press enter then enter code and press enter?

Tried all the ways I can think of but nothing works

April 29, 2014, 10:08
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rehncv

Did not work on Windows Vista Home Basic. Service Pack 2. 

Command prompt (C:\Users\owner>) responded with;

"The requested operation requires elevation."

..., What does that mean?

May 3, 2014, 00:01
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rotblitz

"The requested operation requires elevation."

You need to learn to read.  Again copying from above:

Start > All Programs > Accessories > Right-click "Command Prompt" > Select "Run as Administrator"

 

May 3, 2014, 04:07
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rehncv

rotblitz,  I read just fine.  The instructions should have been more clear.  I took YOUR advice;  It worked.  Thnx.

May 3, 2014, 09:46
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