Flush DNS is a command that help clears outdated or corrupted DNS resolver cache. It typically help fix network connectivity related issues.
For example: If you are having trouble accessing a specific website even after clearing the browsers cookies/history/cache and other website are working fine. You may want to try clearing the DNS cache on your Apple computer.
For Windows: Flush DNS Cache on Windows
For Chrome OS: Flush DNS Cache on Chrome OS
Flush DNS Responder Cache:
| 1 | Click on Go menu on Finder menubar and select Utilities |
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| 2 | Double click on Terminal |
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| 3 | Type in sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder and hit enter |
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| 4 | It will prompt for you password, type in the computer password and hit enter and give it a moment to run When you type the password, nothing will show up. You just need to make sure you are typing it in correctly. |
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| 5 | Close the terminal |
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| 6 | In your browser, clear the cookies/history/cache: For Chrome: https://support.google.com/accounts/answer/32050 For Firefox: https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox - go to section"Clear all cookies, site data and cache" | no image |
| 7 | Exit all browser and relaunch browser. Try visiting the website again | no image |
This will work for:
- OS X El Capitan (10.11)
- macOS Sierra (10.12)
- macOS High Sierra (10.13)
- macOS Mojave (10.14)
- macOS Catalina (10.15)
| 1 | Click on Go menu on Finder menubar and select Utilities |
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| 2 | Double click on Terminal |
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| 3 | Type in sudo killall -HUP mDNSResponder and hit enter |
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| 4 | It will prompt for you password, type in the computer password and hit enter and give it a moment to run. |
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| 5 | Close the terminal |
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| 6 | In your browser, clear the cookies/history/cache: For Chrome: https://support.google.com/accounts/answer/32050 For Firefox: https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox - go to section"Clear all cookies, site data and cache" | no image |
| 7 | Exit all browser and relaunch browser. Try visiting the website again | no image |
