DNS cache: How to flush (clear) it?

In the digital age, quick and efficient internet access is more than just a convenience—it’s a necessity. One critical yet often overlooked component of your internet experience is the DNS cache. This temporary database, maintained by your computer’s operating system, stores recent visits and attempted visits to websites and other domains. However, if the cache becomes outdated or corrupt, it can lead to connection issues and hinder your browsing speed. Flushing, or clearing, your DNS cache can resolve these problems, ensuring that your internet access is both fast and secure. This guide will provide step-by-step instructions on how to flush your DNS cache across various operating systems.

What is DNS Cache?

Before diving into the flushing process, let’s briefly touch on what the DNS cache is. DNS stands for Domain Name System, the internet’s equivalent of a phone book that translates human-friendly web addresses into computer-friendly IP addresses. Your DNS cache, therefore, is like a temporary phone book that stores recent domain lookups, so your computer doesn’t have to reach out to a DNS server every time.

Why Flush Your DNS Cache?

Flushing your Domain Name System cache can be beneficial for several reasons:

• Resolving Connectivity Issues: If you’re unable to access a website or experiencing slow internet speeds, flushing the cache can help.
• Updating Internet Settings: After changing your DNS server settings, flushing the cache ensures that your computer uses the new configuration.
• Privacy and Security: Clearing your cache removes the history of websites you’ve visited, which is a good privacy practice.

How to Flush Your DNS Cache

Windows

1. Open Command Prompt: Press the Windows key, type “cmd”, and select “Command Prompt” from the results. You can also press Windows + R, type “cmd” into the Run dialog, and press Enter.
2. Run the Flush Command: In the Command Prompt window, type the following command and press Enter: ipconfig /flushdns
3. Confirmation: If successful, you’ll see a message stating, “Successfully flushed the DNS Resolver Cache.”

macOS

1. Open Terminal: Open Spotlight by pressing Command + Space, type “Terminal”, and press Enter. You can also find Terminal in the Utilities folder within Applications.
2. Run the Flush Command: The command varies by macOS version. For macOS 10.15 (Catalina) and newer, type sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder and press Enter. Enter your password when prompted.
3. Confirmation: macOS does not typically show a confirmation message, but if you don’t see an error, the cache has been flushed.

Linux

1. Open Terminal: You can usually open Terminal by searching for it in your applications menu or by using a shortcut, often Ctrl + Alt + T.
2. Check for nscd: Not all Linux distributions use nscd for DNS caching. If yours does, proceed with the following command. If not, your system may not cache DNS or may use a different service.
3. Run the Flush Command: Type sudo systemctl restart nscd and press Enter, entering your password if prompted.

Android

1. Restart Your Device: Android does not offer a built-in option to flush the DNS cache specifically. However, restarting your device can effectively do this.

iOS (iPhone and iPad)

1. Enable Airplane Mode: Go to Settings and toggle Airplane Mode on, wait a few seconds, and then toggle it off. This simple action can flush the Domain Name System cache on iOS devices.

Conclusion

Flushing your DNS cache is a quick and effective way to solve connectivity issues and ensure that your internet browsing is as fast and secure as possible. Whether you’re a Windows, macOS, Linux, Android, or iOS user, following the appropriate steps for your system can lead to a smoother internet experience. Remember, this process can be repeated as needed, especially when facing persistent internet issues or after changing your network settings.