E.g., to see the effect of VPN issues getting fixed while connected to the VPN. # Windows ``` ipconfig /flushdns ``` # Mac ``` sudo killall -HUP mDNSResponder ``` # Linux ``` sudo /etc/init.d/nscd restart # OR sudo /etc/init.d/dnsmasq restart # OR sudo /etc/init.d/named restart sudo rndc restart sudo rndc exec ```