You use Telnet commands to control the connection between your PC or laptop and an external system, such as a web server. It is not only important to know the corresponding commands, but also which are appropriate. This is because Telnet commands are only effective when parameters are specified. Read on to find out more.
A regular DNS flush is useful for several reasons. In Windows, macOS, and Linux distributions like Ubuntu, the web address cache is cleared in a few steps.
Clear DNS cache in Windows, Mac, and Linux – here’s how
Each operating system deals with internally stored entries for address resolution differently. To clear the DNS cache because, for example, the DNS server is not responding, you need system-specific tools and commands. Here are some instructions for the most important representatives.
Clear DNS cache in Windows 11: here’s how
As a Windows 11 user, you can conveniently clear the DNS cache via the command prompt. To do this, start the tool via the ‘Run’ dialogue by pressing the key combination [Windows] + [R] and executing the ‘cmd’ command.
Confirm the command by pressing enter. Windows 11 will begin to clear the DNS cache and notify you if the process was successful.
Clear DNS cache in Windows 10: tutorial
Clearing the DNS cache in Windows 10 is just as easily done via the command prompt. For a convenient start of the command line application, use the key combination [Windows] + [R] and then enter ‘cmd’.
Once the DNS cache is cleared, a notification is displayed.
Clear DNS cache in Linux distributions: step-by-step
Linux distributions do not use a native DNS cache. Address entries are only cached on the systems when DNS services such as dnsmasq, nscd or systemd-resolved (default in Ubuntu 18 and 20) are used.
A terminal command for deleting the cache memory is only available for systemd-resolved:
sudo systemd-resolve --flush-caches
To execute the command, simply enter the administrator password. Don’t be surprised if the command does not return a message. To verify that the deletion was successful, you can view the systemd-resolved cache by executing the following terminal command:
sudo systemd-resolve --statistics
You can empty the caches of other DNS services such as dnsmasq and nscd by restarting the services. The appropriate commands in this case are ‘sudo service dnsmasq restart’ and ‘sudo service nscd restart’.
Clear DNS cache in macOS
Mac operating systems, like Windows systems, rely on a native DNS cache. However, the command you need to type to clear the DNS cache varies depending on the version you installed. In any case, you need the terminal for the input, which you can call up via the ‘Utilities’ menu.
For macOS versions 10.11 (El Capitan) and later, as well as 10.7, 10.8, and 10.9, the clear command is as follows:
sudo killall -HUP mDNSResponder
If you are using a device with macOS 10.10 (Yosemite), you need the following command:
sudo discoveryutil udnsflushcaches
Older versions like macOS 10.5 and 10.6 use the following command:
sudo dscacheutil -flushcache
After entering the corresponding command, you will be prompted to enter the administrator password. The DNS cache will then be cleared.
Using a mobile Apple device with iOS? Clear the DNS cache by temporarily activating flight mode. Wait five to ten seconds and switch off the offline mode.