Fun with DNS: Three Useful Commands

The DNS is a distributed, hierarchical database where authority flows from the top (or root) of the hierarchy downward.

When thinking of the structure of the DNS, imagine an inverted tree. Each branch of the tree is within a zone of authority; however, multiple branches of the tree can be within a single zone.

The software (Bind being the most common) that stores domain name information is called a domain name server. A single name server can be authoritative for multiple zones. All zones have a primary master and a secondary master name server that provides authoritative responses for their zones.

If you query a name server not authoritative for a particular zone, that name server will most likely have up-to-date information. This is because zone information propagates throughout the Internet at regular intervals, and name servers cache zone information for which they are not authoritative.

DNS Commands

There are three crucial commands that can put all the DNS information you need at your fingertips. The way to use this article is to try each of the commands listed on a domain name, so you can see what the output looks like. Learn by doing!

Zone file database records divide DNS information into three primary types: NS (Name Server) records, MX (Mail Exchange) records, and A (Address) records. NS records indicate the name servers. MX records indicate the hosts that handle e-mail delivery; the priority (pri) number indicates the order in which mail servers are used, with the lowest number receiving the highest priority. The A (Address) records map hostnames to IP addresses, the real names of machines.

host

This is the simplest of the DNS commands. It is a quick way to determine the IP address of a hostname:

: host www.your-domain-name.com

The -a option will return all of the DNS information in verbose format.

: host -a www.your-domain-name.com

Now that you know the IP address for www.your-domain-name.com, try a reverse lookup.

: host IP-ADDRESS

dig (domain information groper)

This command gathers and returns DNS information in a format the name server can use directly. You will find it easy to query specific name servers with dig.

You can quickly determine the Name servers of your host or any other host:

: dig ns your-host.com

Then you check your (or another) website against the host's name servers:

: dig www.your-domain-name.com @ns.your-host.com

Dig can provide output that is in the same format as the zone file itself. Here is how to get the whole zone file:

: dig any your-domain-name.com

Here are the most useful dig query types: dig any (gathers all DNS information), dig ns (gathers name server information), dig mx (gathers mail exchanger information) and dig a (gathers network address information).

The dig command can also do reverse lookups with output formatted for the zone file:

: dig -x IP-Address

nslookup

You can use this tool as a single line command, or you can use it interactively, which distinguishes it from the other DNS commands. Once you have started nslookup, type set all to list the default options. As with dig you can choose the server (name server) you want to query, and you can decide the type of DNS information on which to focus.

Just as you can issue commands to nslookup interactively, you can also change the initial defaults by starting a .nslookuprc file. The format of the .nslookup is one command per line:

set type=NS
set domain=srvns.your-host.com
set timeout=10

Conclusion

These three commands can provide you with most of the information you need about your domain names. They are powerful tools, and this article should provide you enough information to get started or offer a quick refresher if you already use these commands.

About the Author:

Dan Forootan founded ez publishing, inc. in 1998. EZ Publishing's ez publishing, inc. provides the essential tools for using the Web as a marketing tool. The package includes web hosting, the ez publishing, inc. solution. Please email questions or comments about this article to ez publishing, inc.. Thank you.

eco-friendly cleaning service Buffalo Grove ..
In The News:

AutoFlight's zero-carbon floating vertiport uses solar power to charge eVTOL aircraft while supporting emergency response, tourism, and marine energy maintenance.
A new phone return scam targets recent buyers with fake carrier calls. Learn how criminals steal devices and steps to protect yourself from this fraud.
New Anthropic research reveals how AI reward hacking leads to dangerous behaviors, including models giving harmful advice like drinking bleach to users seeking help.
The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.
Holiday email scams, including non-delivery fraud and gift card schemes, spike in November and December, costing victims hundreds of millions, the FBI says.
Holiday visits offer the perfect opportunity to help older parents with technology updates, scam protection and basic troubleshooting skills for safer digital experiences.
Swiss scientists create grain-sized robot that surgeons control with magnets to deliver medicine precisely through blood vessels in medical breakthrough.
Researchers exploited WhatsApp's API vulnerability to scrape 3.5 billion phone numbers. Learn how this massive data breach happened and protect yourself.
Travel companies share passenger data with third parties during holidays, but travelers can protect themselves by removing data from broker sites and using aliases.
Xpeng's humanoid robot moves so realistically that crowds believed it was fake, marking a major advancement in robotics technology ahead of 2026 commercial launch.
Researchers discover phishing scam using invisible characters to evade email security, with protection tips including password managers and two-factor authentication.
iPhone and Android users can reduce battery drain and data usage by restricting Background App Refresh to Wi-Fi connections instead of mobile networks.
Scammers nearly stole an Apple account by exploiting the support system with authentic-looking tickets and phone calls, users can protect themselves with safety steps.
FoloToy restored sales of its AI teddy bear Kumma after a weeklong suspension following safety group findings of risky and inappropriate responses to children.
Threat intelligence firm Synthient uncovers one of the largest password exposures ever, prompting immediate security recommendations.
Viral video shared by Elon Musk shows Tesla's Optimus humanoid robots performing tasks from cooking to construction, garnering over 58.5 million views on social media.
Chinese hackers used Anthropic's Claude AI to launch autonomous cyberattacks on 30 organizations worldwide, marking a major shift in cybersecurity threats.
Apple's new Sleep Score feature gives you a rating for your nightly rest quality. Learn how to set it up on your Apple Watch and iPhone today.
Essential phone settings to enable before losing your device, including Find My network, location services and security features for iPhone and Android.
The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.
Cybersecurity research shows weak passwords remain a major threat, with simple patterns and number sequences putting millions of accounts at risk.
New Android malware BankBot YNRK silences phones, steals banking data and drains crypto wallets automatically. Learn how this advanced threat works.
FDA approves first human trial for Paradromics' brain-computer interface that could restore speech for paralyzed patients through neural technology.
New phishing platform QRR targets Microsoft 365 users across 1,000 domains in 90 countries. Learn how to spot fake login pages and protect your accounts.
OpenTable now uses AI to track your dining habits and share insights with restaurants. Learn what data they collect and how to protect your privacy.

Finding a reliable hosting provider

The website hosting business is very competitive these days with... Read More

The Domain Name Gold Rush

All the good ones are taken. The really good ones,... Read More

Web Hosting Service ? What you Need to Know to Change Web Hosting Providers

When service at your web hosting company is lacking, or... Read More

How to Find a Dependable Web Host

Your new website is ready to upload, and now you... Read More

Top 10 Web Hosting Blunders and How to Avoid Them

Consider the following web hosting blunders and do not allow... Read More

Finding the Right Web Host

Choosing the right Web Hosting service for your website can... Read More

Dedicated Server Price Check

The price of dedicated hosting services has really come down... Read More

Web Hosts - Not All Are Created Equal

Many people think that all web hosts offer the same... Read More

Choosing the Right Web Host

Whatever type of website you want to host, choosing the... Read More

How to Choose a Web Host - Frequently Asked Questions

In this article you'll be provided with helpful information about... Read More

The Ups and Downs of Dedicated Server Hosting

Getting your own dedicated server for your business is a... Read More

How To Host Several Websites Under One Account

If you operate several websites, each with its own domain... Read More

Web Site Hosting For Your Business ? Free or Paid?

It's time to choose! Should you spend some money to... Read More

Cheap Web Hosting Package? eCommerce Web Hosting? - Choosing A Web Hosting Provider

One of the important decisions you'll make when you decide... Read More

How To Have Several Websites But Pay For Only One Websites Hosting

Many online entrepreneurs these days are faced with the problem... Read More

Best Website Hosting is One Thats Reliable

If you are looking for a solid, reliable web host,... Read More

Steps to Becoming a Web Host Reseller

You've decided to get a reseller web hosting account to... Read More

Webhosting for Blogs - Free or Paid Service

Blogging is an abbreviation of "web-logging". The simplest definition of... Read More

Why Dedicated Hosting?

If you're reading this article, you might be interested in... Read More

The 2 Sides of Reseller Web Hosting

In the first case the customer is really looking for... Read More

Dedicated Web Hosting : The Executive Summary

What is Dedicated Web Hosting? Dedicated web hosting can alleviate... Read More

Domain Name and Web Hosting Hell

Does GoDaddy really suck?I am in the process of registering... Read More

What is a Web Host Reseller Account?

A web host reseller account is a web hosting account... Read More

Free Web Hosting

There is no concept of free lunch in the world,... Read More

Linux vs. Windows Web Hosting, Does It Make A Difference?

One of the most confusing decisions someone new to web... Read More

express cleaning service Arlington Heights ..