Clear DNS cache on macOS

To clear your local DNS cache on macOS do the following:

dscacheutil -flushcache
sudo killall -HUP mDNSResponder

A simple wrapper for this (that might go in your bashrc) would be:

function clear_dns_cache() {
  echo "Clearing local DNS cache..."
  dscacheutil -flushcache
  sudo killall -HUP mDNSResponder
}