Overview

Your DNS cache stores locations (IP addresses) of web servers that contain pages which you have recently viewed. If the location of the web server changes before the entry in your DNS cache updates, you will be unable to access the site.

If you encounter a large number of HTML 404 error codes, you may need to clear your DNS cache. Once you clear your DNS cache, your computer will query nameservers for the new DNS information.

How to clear your DNS cache

The following methods allow you to remove old and inaccurate DNS information that may result in 404 errors.

Windows® (Modern Versions: 10, 11, 8, 7)

1. Open Command Prompt:
   • Press Windows Key + R to open the Run dialog box.
   • Type cmd and press Enter.
2. In the Command Prompt, type the following command and press Enter:

   ipconfig /flushdns

3. You should receive a message that the DNS cache was successfully flushed.

Windows® XP, 2000, or Vista®

1. Click the Start button.
2. On the Start menu, click Run.
3. If you do not see the Run command in Vista, enter "run" in the Search bar.
4. Type the following in the Run text box:

   ipconfig /flushdns

MacOS® (Modern Versions: 10.15 - 14.x)

1. Open Finder.
2. Go to Applications > Utilities.
3. Double-click the Terminal application.
4. Type the following command and press Enter:

   sudo killall -HUP mDNSResponder

   Note: You will need to enter your Admin account password to run this command.

MacOS® 10.7 - 10.14

1. Open Finder.
2. Go to Applications > Utilities.
3. Double-click the Terminal application.
4. Type the following command and press Enter:

   sudo killall -HUP mDNSResponder

   Note: You will need to enter your Admin account password to run this command.

MacOS® 10.5 and 10.6

1. Open Finder.
2. Go to Applications > Utilities.
3. Double-click the Terminal application.
4. Type the following command and press Enter:

   dscacheutil -flushcache

Linux (Modern Distributions)

Most modern Linux distributions use systemd-resolved or other DNS resolvers. Use the following commands based on your distribution:

1. systemd-based systems (Ubuntu, Fedora, etc.):
   • Open a Terminal window.
   • Type the following command and press Enter:

     sudo systemctl restart systemd-resolved

   • You may need to enter your Admin account password.
2. Other Linux distributions using nscd (Name Service Cache Daemon):
   • Open a Terminal window.
   • Type the following command and press Enter:

     sudo /etc/init.d/nscd restart

   • Note: You may need to install nscd if it's not already installed.