Your DNS cache stores the locations (IP addresses) of web servers that contain web pages which you have recently viewed. If the location of the web server changes before the entry in your DNS cache updates, you can no longer access the site.
If you encounter a large number of HTML 404 error codes, you may need to clear your DNS cache. After you clear your DNS cache, your computer will query nameservers for the new DNS information.
MacOS 10.10.4 and above
To clear your DNS cache if you use MacOS X version 10.10.4 or above, perform the following steps:
- Click Applications.
- Click Utilities.
- Click Terminal.
- Run the following command:
sudo killall -HUP mDNSResponder
If the command succeeds, the system does not return any output.
To clear your DNS cache if you use MacOS X version 10.10 through 10.10.3, perform the following steps:
- Click Applications.
- Click Utilities.
- Click Terminal.
- Run the following command:
sudo discoveryutil mdnsflushcache
If the command succeeds, the system does not return any output.
MacOS 10.7, 10.8, or 10.9
To clear your DNS cache if you use MacOS X version 10.7, 10.8, or 10.9, perform the following steps:
- Click Applications.
- Click Utilities.
- Double-click Terminal.
- Run the following command:
sudo killall -HUP mDNSResponder
If the command succeeds, the system does not return any output.
MacOS 10.5 or 10.6
To clear your DNS cache if you use MacOS X version 10.5 or 10.6, perform the following steps:
- Click Applications.
- Click Utilities.
- Double-click Terminal.
- Run the following command:
sudo dscacheutil -flushcache
If the command succeeds, the system does not return any output.
