If you are unable to access certain websites, or have DNS problems when trying to visit certain pages on the web, flashing or clearing your DNS cache may help resolve the problem. We explain to you what it means and how to do it on Windows and also on a Mac.
In the dictionary of computer networks, and when you type an address of a website (The URL) in the address bar of your web browser, such as TechCroute.com, for example, your computer does not directly understand your request made up of numbers and letters. And in order for it to be able to provide you with an answer, in this case, a web page or website you want to view, it must match the domain name (website) requested with its IP address. . For him without an IP address, he can never identify a website and this is the norm in networks.
It’s as if you want to go to Galeries Lafayette in Nice and you don’t know where the store is exactly, a little search for its address in a phone book or on Google Maps will surely help you find it there. return. It’s the same concept in IT!
So your computer and to find a website it uses a lookup table, a directory that contains the domain name (website) and its corresponding IP address, and it’s called in computer jargon, DNS servers.
We are not yet finished with the definitions, and so that the computer receives the responses of these DNS servers (Domain names equivalent to IP addresses) more quickly and to speed up this search process, it records the requests (the matches between domain name and IP) of sites that you have already visited without having to go and ask the DNS server each time and this is where your computer uses the DNS cache.
And like the browser cache, the DNS cache can cause problems accessing a site, in the case, for example, where the cached IP address is no longer the same as the site (in the event of a change of IP address of a website), or even in the case of malware in your operating system that tries to redirect the sites you request in the address bar to other addresses and sites malicious.
Either way, you can “flush” your DNS cache to start over, so that your computer will look for web addresses on the DNS Server again.
How to flash or clear your DNS cache
This process is, of course, different from clearing your web cache from a web browser. If clearing your browser’s cache did not resolve the issue, clearing your DNS cache may be the next step. So here’s how:
Flash and clear your DNS cache on Windows
If you are on a Microsoft Windows computer, from Windows XP to Windows 10, a single command in the system terminal (cmd.exe) is enough to clear your PC’s DNS cache.
To do this, open the Windows command prompt in administrator mode (Right-click on Start then select Command prompt (Admin)) or (Windows key + Q, type CMD and validate with shift + Ctrl + ENTER, or the Windows key + “X” and click on “command prompt (admin)) and in the command prompt window that appears, type the following command:
There you go, try to revisit the problematic site again.
How the flusher and dump it on Mac
Mac users need to run a command in Terminal to flush the DNS cache, but the command differs depending on your version of macOS:
First, press cmd + Space to open Spotlight and search for ” Terminal »Then press Entrance to open it.
Most of the latest versions of macOS, from OS X Lion to macOS Sierra, use the following command to type in the terminal:
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
But if you are on OS X version 10.10.1, 10.10.2, or 10.10.3, type the following command to clear your DNS cache on Mac:
sudo discoveryutil udnsflushcaches;sudo discoveryutil mdnsflushcaches
Now try to visit the problematic site again on your Mac.