The Origin Story (1986)

nslookup was created in 1986 by Andrew Cherenson while he was a student at the University of California, Berkeley.

• Context: It was developed as a class project.
• First Release: It was officially distributed with the 4.3 BSD (Berkeley Software Distribution) Unix release (specifically the “Tahoe” release).
• Purpose: It was designed as part of the BIND (Berkeley Internet Name Domain) software suite, which effectively built the foundation for how DNS works on the internet today.

When did it come to Windows?

According to Google, nslookup started on Unix (the basis of most Linux distributions) and arrived on early Windows a few years later.

• First Windows Appearance: It was included in Windows NT 3.1, released in 1993.
• Note: It was originally a “pro” tool found in the business-focused Windows NT line. It wasn’t natively included in the consumer-focused Windows 95 or 98 (users had to download third-party tools back then), but it became standard for everyone once Windows XP merged the consumer and professional lines.

A Fun Bit of Drama

In the early 2000s, the organization that maintains BIND (the ISC) actually deprecated nslookup, labeling it as obsolete and trying to replace it with newer tools like dig and host.

• The Result: The IT community largely ignored them. nslookup was so deeply ingrained in muscle memory and scripts that the decision was eventually reversed, and it remains fully supported today.

What nslookup Is Used for and Why I Trust It

I have used nslookup since it first became available decades ago. Back then, DNS troubleshooting tools were limited, so nslookup felt powerful. Simply put, nslookup asks DNS servers questions and shows their answers. Because of that, it helps explain why a domain works or fails.

In everyday terms, nslookup lets me peek behind the Internet curtain. Instead of guessing, I can see real DNS data instantly.

Why a Beginner Might Need nslookup

Many people think websites either work or they don’t. However, DNS problems often hide behind the scenes. With nslookup, I can confirm where a domain really points.

For example, email delivery issues often trace back to DNS. Likewise, website moves rely heavily on correct DNS records. Therefore, nslookup becomes a fast reality check.

Opening nslookup in Windows

Using nslookup in Windows is refreshingly simple: First, I open the Command Prompt. On Windows 7, Windows 10, or Windows 11, this works the same.

I click Start, type cmd, then press Enter. Once the black window appears, I type nslookup and press Enter.

At this point, nslookup is running interactively.

Basic nslookup Usage in Windows

After nslookup starts, it shows the default DNS server. Usually, this is your Internet provider or Google DNS.

Next, I type a domain name and press Enter.

For instance, typing google.com returns multiple DNS records, as shown in my example on this page. These include IP addresses and mail servers. Therefore, I immediately learn how traffic is routed.

👉 NOTE: In Windows, you can copy data from your Command Prompt screen by clicking on the small C:\. icon in its upper left corner of the window, mousing down to Edit and clicking on Mark. Then use your mouse to highlight the text you want to copy and press Enter to move that text into your copy buffer. You can then past it using CTRL-V (standard paste command) into any other window (like email or a document or whatever.

Using Record Types for Better Answers

By default, nslookup shows basic records. However, DNS supports many record types. So, I often change the query type.

For example, I type set type=any.

Then, I query the domain again. As a result, I see text records, mail records, and name servers.

👉 Here’s what the “Command Prompt” screenshot on my desktop machine looks like. Note that on a phone this is more readable when viewed in the landscape (horizontal) mode:

What the Screenshot Is Showing

In the screenshot, nslookup is querying google.com. You can see IP addresses, mail exchangers, and text records. Those text records often contain email security information.

Additionally, the output shows authoritative name servers. This helps confirm who controls the domain’s DNS.

Real-World Reasons I Use nslookup

I rely on nslookup during website migrations. At CharlesWorks, we routinely migrate websites to newer, upgraded servers (at no charge to our web clients) to keep them secure and updated. Before switching servers, I confirm DNS changes propagate correctly. Likewise, email troubleshooting often starts here.

When email fails, I check mail exchanger records first. If those look wrong, the problem becomes obvious quickly. Therefore, nslookup saves time and frustration.

Using nslookup Non-Interactively

Sometimes I want fast answers without the interactive mode. In that case, I run a single command.

For example: nslookup google.com 8.8.8.8

This queries Google’s DNS directly. As a result, I bypass local DNS issues. That trick helps isolate problems faster.

Using nslookup on Debian and Other Linux Systems

I mention Debian because it happens to be my favorite at this point in time. However, nslookup is not limited to Windows. On Debian Linux and most distributions, it works similarly. I open a terminal instead of a Command Prompt.

Usually, nslookup is already installed. If not, I install it with standard package tools. Once installed, usage is nearly identical.

Because of that, my troubleshooting skills transfer easily between systems.

Why nslookup Still Matters Today

Some tools come and go over time. However, nslookup has survived for good reasons. It remains simple, reliable, and universally available.

Even with modern graphical tools, I still trust it. When DNS matters, plain answers matter more. That is why nslookup stays in my toolbox.

Final Thoughts for Beginners

If DNS feels mysterious, nslookup removes the mystery. If you want to start getting into the DNS weeds, check out my article: https://charlesworks.com/dns-101-what-dns-is-and-why-dns-is-essential-for-the-internet/. You don’t need advanced knowledge to get value. You just need curiosity and a few commands.

Start small, experiment safely, and read the results. Over time, patterns will make sense naturally. That’s exactly how I learned this stuff earlier in life.

If all this is beyond you and you have an issue with your website that we handle, please do contact us at 603-924-9867 and someone on staff who understands the issue will look into it for you.