Problem: DNS cache stores the IP addresses of web servers that contain recently viewed web pages. If you encounter lot of HTML 404 error codes due to location of the web server changes before the entry in DNS cache updates, remove old and inaccurate DNS information that may result in 404 errors by using below method, computer will query nameservers for the new DNS information after clearing DNS cache.
Windows 8
Step 1: Press Win+X to open the WinX Menu.
Step 2: Right-click Command Prompt and select Run as Administrator.
Step 3: Run the following command: ipconfig /flushdns
If the command succeeds, the system returns the following message: Windows IP configuration successfully flushed the DNS Resolver Cache.
Windows 7
Step 1: Click Start.
Step 2: Enter cmd in the Start menu search text box.
Step 3: Right-click Command Prompt and select Run as Administrator.
Step 4: Run the following command: ipconfig /flushdns
If the command succeeds, the system returns the following message: Windows IP configuration successfully flushed the DNS Resolver Cache.
Windows XP, 2000 or Vista
Step 1: Click Start.
Step 2: On the Start menu, click Run.
Step 3: If you do not see the Run command in Vista, enter run in the Search bar.
Step 4: Run the following command in the Run text box: ipconfig /flushdns
If the command succeeds, the system returns the following message: Successfully flushed the DNS Resolver Cache.
Reset DNS Cache in macOS High Sierra 10.13.x
Step 1: Click Applications.
Step 2: Click Utilities.
Step 3: Click Terminal.
Step 4: Run the following command: sudo killall -HUP mDNSResponder;echo macOS DNS Cache Reset
Step 5: If the above command doesn’t work, then try this command: sudo killall -HUP mDNSResponder && echo macOS DNS Cache Reset
MacOS 10.10.4 and above
Step 1: Click Applications.
Step 2: Click Utilities.
Step 3: Click Terminal.
Step 4: Run the following command: sudo killall -HUP mDNSResponder
MacOS X version 10.10.1, 10.10.2 and 10.10.3
Step 1: Click Applications.
Step 2: Click Utilities.
Step 3: Click Terminal.
Step 4: Run the following command: sudo discoveryutil mdnsflushcache
MacOS X version 10.7, 10.8 and 10.9
Step 1: Click Applications.
Step 2: Click Utilities.
Step 3: Double-click Terminal.
Step 4: Run the following command: sudo killall -HUP mDNSResponder
MacOS X version 10.5 and 10.6
Step 1: Click Applications.
Step 2: Click Utilities.
Step 3: Double-click Terminal.
Step 4: Run the following command: sudo dscacheutil -flushcache