I changed my router to use Google's public DNS. Now how do I ensure that my router is using Google Public DNS(126.96.36.199) to connect. How do I check what DNS server is being used to connect to the Internet for any service. I am using Windows 7
I know this is an old question, but I thought I can help with another answer.
I don't completely agree with the answer above. nslookup will show you what DNS you are "supposed" to be using but not necessarily the real DNS you are using. You can configure your computer to use a DNS but your router can hijack the DNS call. In that same note, you can set your router to use a DNS and your service provider can hijack the DNS calls to use their DNS server. (I use a linksys router with tomato firmware in it and with iptables rules I am hijacking all DNS calls to use OpenDNS as the DNS service provider.) If you really want to know what DNS server you are using, I recommend you to google "DNS leak test" and test your DNS. Here is one test you can run: https://www.dnsleaktest.com/