If you own a computer running macOS Sierra and have ever modified your DNS settings, you must have needed to flush the DNS Cache, otherwise no changes would have been reflected. In addition, sometimes the servers may not work as you expect. This could be because you have very old Caches on your Mac and wiping them may help resolve the issue.
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This lubrication method uses the command line and therefore should not be attempted by complete novices.
How to clear and reset DNS Cache on macOS Sierra
- From the Utilities folder, launch the Terminal application.
- Paste the following text into it without the quotes. "sudo killall -HUP mDNSResponder; say DNS cache has been flushed"
- Press Enter and optionally insert adminiadministrator password. This step is necessary because of the sudo command.
- Wait a moment.
You will hear a beep when the process is complete. That's why it's good not to have muted sounds to let you know the process is over.
The above command may not work. Fortunately, as of macOS Sierra 10.12.3, an alternative command works in the form of "sudo killall -HUP mDNSResponder;sudo killall mDNSResponderHelper;sudo dscacheutil -flushcache;say MacOS DNS cache has been cleared". So if nothing happens on the first try nestyes, instead of the command in step 2, enter this one.
It's funny how these commands are copied from page to page. The say command is not that necessary, and if you have a system with Czech, a Czech message works better.
And have you already tried, instead of killing the process, you need: dscacheutil -flushcache ?
Oh, my fault. It's that kind of thing (even if it's covered in frills too)