Clearing Your DNS Cache

Are you looking for comprehensive information regarding those methods that can help you clear your DNS (Domain Name System) cache, so that you can remove old and/or inaccurate DNS information, which might be causing 404 errors? Then get ready to know about the various methods that will aid you in attaining your goal.

The locations (IP addresses) of web servers, which contain those web pages that have been viewed recently by you, are stored in your DNS cache. There can be situations where you are unable to access a particular website because the location (IP address) of the web server had changed prior to the entry being updated in your DNS cache. When you come across too many HTML 404 error codes, it is recommended and usually needed that you clear your DNS cache. Once you have cleared your DNS cache, your computer will query new DNS information’s nameservers.

Before we proceed further, let us touch upon what DNS cache and web servers are.

Web Servers

Servers can be of many types. Web servers are one of the types of servers, and are used in web hosting service for storing and processing the files of websites in order to render sites accessible over the Internet. The owners of websites are the clients of the web hosting companies that provide the service of web hosting. Web hosting can be either shared hosting or VPS or dedicated hosting or Cloud hosting or reseller hosting or WordPress hosting. Usually, certain terms are used to refer to the most well-known web hosting service providers. These terms are the “Best Cloud Hosting Company”, the “Best Website Hosting Company”, the “Best Windows Hosting Company”, etc.

A web server’s main function is to accept and fulfil the requests, in the form of Http (Hypertext Transfer Protocol) messages, of clients, such as browsers or mobile applications. These requests are for the content of websites, such as HTML pages, images, videos, etc.

Once a web server receives a request for a certain web content, it delivers the stored files for that web content over the Internet to the client (browser or mobile application) that had requested for it. This is the role that web servers play in web hosting.

DNS Cache

The temporary storage of information with regard to the previous DNS lookups on a web browser or the OS (Operating System) of a machine, is referred to as DNS cache. Maintaining a local copy of a DNS lookup enables one’s browser or OS to retrieve it quickly. This ensures that the URL of a website can be resolved to its corresponding IP efficiently. DNS caching doesn’t take place only at the browser and OS level. There are various steps in a DNS lookup. In a new DNS lookup, the lookup passes through the following: the resolver, the root server, and the TLD (Top-level Domain) server. Information is gathered and cached at each of these steps, so that it can be used later. 

How to Check Your DNS Cache

It is possible for you to check your DNS cache. You can check the logs of your operating system to find out the DNS records that are cached locally. The processes related to it vary and depend on the operating system that is being used. Let us find out how you can check your DNS cache on Windows and Mac. 

Windows- It is not at all difficult to view your DNS cache entries in Windows. You need to open your command prompt, and subsequently enter the below-mentioned command.

ipconfig /displaydns

Mac- For Mac, you need to open the Console app, then you have to select your device from the left side, and enter the below-mentioned command into the search bar.

any:mdnsresponder

Next, you need to open your command line, and then enter the following command:

sudo killall -INFO mDNSResponder

Post this, you should be able to return to your Console app, and view the list of cached DNS records. Moreover, you can also check the entries for your DNS cache on certain browsers. Let us take the example of Chrome. For Chrome, you need to enter the following command into your address bar: chrome://net-internals/#dns

This will return the current list of cached DNS records for your browser.

Ways to Clear Your DNS Cache

You need to follow the below-mentioned methods to remove DNS information that is old and not accurate. We will describe the methods individually for Windows and MacOS versions.

Windows 8

For Windows 8, you need to carry out the following steps to clear your DNS cache-

• Press Win+X on your keyboard. This will open the WinX Menu.

• Right-click Command Prompt.

• Select Run as Administrator .

• Run the below-mentioned command.

          ipconfig /flushdns

• If the command is successful, the following message is returned by the system- Windows IP configuration successfully flushed the DNS Resolver Cache.

Windows 7

For Windows 7, you need to carry out the following steps to clear your DNS cache-

• Click Start.

• Enter cmd in the Start menu search text box.

• Right-click Command Prompt.

• Select Run as Administrator.

• Run the below-mentioned command.

          ipconfig /flushdns

• If the command is successful, the following message is returned by the system- Windows IP configuration successfully flushed the DNS Resolver Cache.

Windows XP, 2000, or Vista

For Windows XP, 2000, or Vista,  you need to carry out the following steps to clear your DNS cache-

• Click Start.

• In the Start menu, click Run....

• Enter run in the Search bar, if you don’t see the Run command in Vista.

• The following command needs to be run in the text box, Run.

          ipconfig /flushdns

• If the command is successful, the following message is returned by the system- Successfully flushed the DNS Resolver Cache.

MacOS 10.10.4 and above

For MacOS X version 10.10.4 and above, you need to carry out the following steps to clear your DNS cache-

• Click Applications.

• Click Utilities.

• Click Terminal.

• Run the below-mentioned command.

          sudo killall -HUP mDNSResponder

• The system does not return any output for a successful command.

An important point that needs to be mentioned here is that you must know the administrator account password of the computer in order to be able to run this command.

MacOS 10.10.1, 10.10.2, and 10.10.3

For MacOS X version 10.10 through 10.10.3,  you need to carry out the following steps to clear your DNS cache-

• Click Applications.

• Click Utilities.

• Click Terminal.

• Run the below-mentioned command.

          sudo discoveryutil mdnsflushcache

• The system does not return any output for a successful command.

You need to know the administrator account password of the computer to run this command.

MacOS 10.5 and 10.6

For MacOS X version 10.5 or 10.6, you need to carry out the following steps to clear your DNS cache-

• Click Applications.

• Click Utilities.

• Double-click Terminal.

• Run the below-mentioned command.

          sudo dscacheutil -flushcache

• The system does not return any output for a successful command.

You need to know the administrator account password of the computer to run this command.

MacOS 10.7, 10 8, and 10.9

For MacOS X version 10.7, 10.8, and 10.9, you need to carry out the following steps to clear your DNS cache-

• Click Applications.

• Click Utilities.

• Double-click Terminal.

• Run the below-mentioned command.

         sudo killall -HUP mDNSResponder

• The system does not return any output for a successful command.

You need to know the administrator account password of the computer to run this command.

Now you know about the various methods that will help you clear your DNS cache easily for Windows as well as for MacOS.

Source: https://www.htshosting.org/knowledge-base/technology/146/clearing-your-dns-cache