If you have recently changed name servers for a domain or have recently registered a new domain, and see errors in your browser like :
This site can not be reached
DNS_PROBE_POSSIBLE
DOMAIN NOT FOUND
This is caused by something known as 'dns propegation'. The DNS system does 'cache' results which can means it can take time for the domain name to resolve.
Flushing your DNS cache can also help, the process to do this is the following.
Specific Instructions for clearing you devices DNS cache
Windows
You must be logged in as an administrator - or you'll need to right-click on Command Prompt and left-click Run as administrator
Access the Command Prompt by either:
- Clicking the Start button and typing
CMD and then pressing Enter. - Clicking the Start button and scrolling to the Windows System folder - left-click to open the folder and the left-click Command Prompt
Then type the following command and press Enter.
ipconfig /flushdns
If the command runs successfully you'll see a message similar to this
Successfully flushed the DNS Resolver Cache
MacOS
This is an administrative level task - so you'll need to know an administrator username & password to complete this successfully - you'll be asked to enter the password once you've run the command.
Open the Terminal application from the Applications/Utilities folder or search for it using Spotlight.
Depending on which version of Mac OSX you are running, you should type in the appropriate command and press Enter.
For Mac OS X prior to 10.5.1 (Leopard)
sudo lookupd -flushcache
Mac OS X 10.5 and 10.6 (Leopard and Snow Leopard)
sudo dscacheutil -flushcache
You can obtain a full list of all entries in the cache using this command.
sudo dscacheutil -cachedump -entries
Mac OS X 10.7, OS X 10.8 and OS X 10.9 (Lion, Mountain Lion & Mavericks)
sudo killall -HUP mDNSResponder
OS X 10.10, 10.10.1, 10.10.2 and 10.10.3 (Yosemite)
sudo discoveryutil mdnsflushcache
OS X 10.10.4 and onwards (Yosemite, El Capitan, Sierra, High Sierra, Mojave, Catalina, Big Sur, Monterey & Sequoia)
sudo killall -HUP mDNSResponder
