Domain NameServer:
The Domain Name System (DNS) translates Internet domain and host names to IP addresses and vice versa.
Domain NameServer Cache:
A DNS Cache stores the information about the recent visits and attempted visits to the websites and other internet domains. It is just a memory of recent DNS lookups that can be quickly referred while loading a website. If the error 404 occurs frequently, then the DNS cache should be cleared. DNS cache can be cleared by using flush DNS.
Steps to clear DNS Cache:
1. To clear the DNS cache in Windows OS, run the following command in the CommandPrompt
ipconfig/flushdns
2. To clear the DNS cache in MacOS 10.10.4 and above, run the following command in the Terminal
sudo killall -HUP mDNSResponder
3. To clear the DNS cache in MacOS X version 10.10 through 10.10.3, run the following command in the Terminal
sudo discoveryutil mdnsflushcache
4. To clear the DNS cache in MacOS X version 10.7, 10.8, or 10.9, run the following command in the Terminal
sudo killall -HUP mDNSResponder
5. To clear the DNS cache in MacOS X version 10.5 or 10.6, run the following command in the Terminal
sudo dscacheutil -flushcache