Most Smart DNS services no longer work to watch Netflix. This is because Netflix works hard to block as many IPs as possible. Netflix has already blocked IP addresses associated with the majority of Smart DNS services, so they will not work. That said, some market-leading VPNs also throw in a free Smart DNS service. These VPNs make it part of their mission to keep providing IPs that work with Netflix. This should mean that the Smart DNS service provided by the VPN works (as well as the VPN itself) to watch Netflix. The only thing to remember is that the Smart DNS services provided by VPNs are usually only set up to provide you with an IP address in America. This means that the Smart DNS service will only let you access the US Netflix library. You will still need to use the full VPN client to access other Netflix regions.