Clearing your local DNS Cache30 Aug 2017Development While editing DNS settings for a client (or for yourself) and the URL’s don’t resolve like they should, it’s probably your local DNS Cache fooling you.It would be a good idea to clear your local DNS Cache. For macOS Sierra 10.12.0, OSX 10.11.0, OSX 10.10.4 and OSX 10.9 – 10.8 – 10.7 you can use this. sudo killall -HUP mDNSResponder For OSX 10.10.0 – 10.10.3 you can use this. sudo discoveryutil mdnsflushcache For OSX 10.5 – 10.6 you must use this. sudo dscacheutil -flushcache