How to find out DNS server IP used by my router

I am using Comcast. And my router is set up to acquire DNS server automatically. How can I find out the IP address of the DNS server used by my router? I am using Windows. Is there some Windows command that I can use?

Solution 1:

You can do one of two things:

1. If your router is just passing Comcast's DNS servers then you can issue an ipconfig /all at the command line and it will tell you (Comcast's servers would be 68.xx.xx.xx not 192.168.xx.xx)

2. If your router is passing itself as the DNS server, then you should be able to go on the router's admin interface status page and see what DNS servers it got from comcast's DHCP server.

Solution 2:

I can't find the link right now but there are DNS-based domains which will accept a query and return the IP address of the requesting DNS server as the "resolved" answer. They won't report all your configured DNS servers but they could be useful when you don't have access to the DNS box.

A web-based page which include this info is http://www.dnsstuff.com/tools/aboutyou/

Solution 3:

Running the recently released Namebench will tell you what DNS server you're using and will also tell you if there are faster ones available.

Word of warning it takes a few minutes to run, but the results are enlightening.

Solution 4:

You can use the nslookup command to check DNS resolution.
Open a cmd terminal window (Start -> cmd > run). Type:
nslookup www.google.com
The first two lines are the domain server you are using

In my case:
C:> nslookup www.google.com
Server: cns.sanjose.ca.sanfran.comcast.net
Address: 68.87.76.182
[...]

my dns is 68.....