This post will cover how to use the “nslookup command”. You are going to want to use the “nslookup command” when ever you are trying to troubleshoot DNS issues. I will walk through looking up A Host Records as well as PTR Records.
How to Run “nslookup”.
You are going to need to open a command prompt. To do this in Windows go to “START” – “RUN” – and then type “cmd”. This will open the command prompt.
Once the command prompt is up and running you are going to want to type in: “nslookup”
You will notice that you are given two pieces of information.
- Default Server: This is the default DNS server that your machine is using.
- Address: This is the IP address of the DNS server that your machine is using.
Underneath this info from the nslookup command you will see this:
This is where you are going to be able to type in “Filters”. These filters are going to be like “MX”, A Records , or PTR records. For example to turn on the filter in nslookup to only show MX records you would type:
You have now set the filter “Type” to MX. This will now only display MX records. Here’s the output from me looking up Google’s MX records.
Another command you might want to try is setting the filter to type=PTR. That is Reverse Lookup.