The nslookup (which stands for name server lookup) command is a network utility program used to obtain information about internet servers. It finds name server information for domains by querying the Domain Name System.
How to Find an IP With the Mac Address and Reverse Lookup. However, by using one simple tool and the MAC address of the device for which you need to find the IP address, you can obtain the IP address in minutes. Find an IP address using a MAC address. Dig (on Mac OS X and Linux) and nslookup (on Microsoft Windows) are the primary command-line tools for troubleshooting DNS issues. While web-based tools are convenient and easy to use, it is often faster to use a command-line tool on your own system.
Most computer operating systems include a built-in command line program with the same name. Some network providers also host web-based services of this same utility (like Network-Tools.com). These programs are all designed to perform name server lookups against specified domains.
How to Use nslookup in Windows
To use the Windows version of nslookup, open Command Prompt and type nslookup to get a result similar to this one but with entries for the DNS server and IP address that your computer is using:
This command identifies which DNS server the computer is currently configured to use for its DNS lookups. As the example shows, this computer is using an OpenDNS DNS server.
Take note of the small > at the bottom of the command's output. nslookup remains running in the background after the command is issued. The prompt at the end of the output lets you enter additional parameters. When you execute nslookup without specifying a domain name, the program enters interactive mode.
Either type the domain name you want the nslookup details for or quit nslookup with the exit command (or the Ctrl+C keyboard shortcut). You could instead use nslookup by typing the command before the domain, all on the same line:
Here's an example output:
Nameserver Lookup
In DNS, so-called 'non-authoritative answers' refer to DNS records kept on external DNS servers, which they obtained from the 'authoritative' servers that provide the original source of the data.
Here's how to get that information (assuming you've already typed nslookup into Command Prompt):
An authoritative address lookup can be performed by specifying one of the domain's registered nameservers. Nslookup then uses that server instead of the default DNS server information of the local system.
The output no longer mentions 'non-authoritative' data because the nameserver ns1.p30.dynect is a primary nameserver for Lifewire.com, as listed in the 'NS record' portion of its DNS entries.
Mail Server Lookup
To search for mail server information on a particular domain, nslookup uses the MX record feature of DNS. Some sites, like Lifewire.com, support both primary and backup servers.
Mail server queries for Lifewire.com work like this:
Other nslookup Queries
![Tool Tool](/uploads/1/2/6/5/126548455/999309677.png)
Nslookup supports querying against other less commonly used DNS records including CNAME, PTR, and SOA. Typing a question mark at the prompt prints the program's help instructions.
Some web-based variations of the utility offer a few additional features beyond the standard parameters found within the Windows tool.
How to Use Online Nslookup Tools
Online nslookup utilities, like the one from Network-Tools.com, lets you customize a lot more than what's allowed with the command from Windows.
Web Nslookup
For example, after choosing the domain, server, and port, you can pick from a drop-down list of query types like address, nameserver, canonical name, start of authority, mailbox domain, mail group member, well-known services, mail exchange, ISDN address, NSAP address, and many others.
Screenshot Tool For Mac
You can also pick the query class; internet, CHAOS or Hesiod.