How to lookup a user name and machine name using an IP address (on windows)

If you need to find a username but only have an ip address, if you use active directory (AD) then you can use the following method to find out the username:

1. At the command prompt enter the following command:

nbtstat –a ipaddress

Where ipaddress is the ip address.
This will list the machine name using that ip address.

2.Then run the following command:

net view /domain:ad > somefile.txt

Where ad is the name of the domain you want to search and somefile.txt is the name of the file to contain the output.
This will generate a list of every machine and who is logged in. 

3.Open the output file and search for the machine name determined in step 1 (the username will be listed next to this).

HTH

Tim