Life is hard enough without taking time out from the daily grind to contemplate complex topics, like epistemology, scattering theory and when, exactly, Glee jumped the shark. But sometimes you need to make that extra intellectual effort — like when you’re trying to understand why your website isn’t popping up after you type its name in your browser bar. Case in point: DNS. What is the domain name system, better known as DNS? And is this something I need to know?
Short answer? Yes.
Before I started working at a tech company, I might’ve said DNS stood for “Don’t Nuzzle Saxophonists” or “Dance Nebulous Salesman.” Now I know that it’s short for Domain Name System — the thing that provides visitors access to a website using a domain name (like coolexample.com) rather than an IP address (a long string a numbers you’ll learn more about soon).
DNS translates the text-based website or location identifier a visitor enters (domain name) to the number-based IP address of the associated website or Internet location.
It might not be as complicated as quantum mechanics, but DNS is a bit tricky to wrap your brain around. Here’s some info that might help break it down into more palatable pieces. Like cookies.
What is the domain name system?
To start understanding DNS, you need to get a grip on its basic elements. So here’s a DNS glossary, or, as I like to call it, DNSsary.
DNS is like the phone book for the internet. It translates human-speak into computer-speak by connecting a name (your domain name) to an address (your IP address). For example, you only have to remember coolexample.com (domain name), not 126.96.36.199 (IP address), to access that website.
Using DNS, we can enter easily remembered, text-based domain names and reach machine-readable internet addresses.
IP addresses are strings of numbers every computer connected to the internet uses to identify a website’s location and communicate with other computers and web servers. You can think of an IP address like a website’s street address.
Fun fact for geeks: IP stands for Internet Protocol.
Each domain name stores its DNS information in a zone file. Large collections of zone files for different domain names are stored on nameservers. A domain name must point to the nameserver holding its specific zone file. Here’s another way to think about it: DNS (paper) goes in a zone file (folder), which goes in a nameserver (filing cabinet). Nifty, huh?
An A record, or host record, is like a middle-man. It’s the record in your zone file connecting your domain name to your IP address, typically your web server. Picture an Oreo cookie. The domain name and IP address are the cookies and the A record is the cream filling in the middle that connects them. (Yes, I like cookies.)
A CNAME is an alias for an A record that makes your DNS data easier to manage. CNAMEs let you have more than one DNS name for an A record (or any other DNS record). If you change the IP address of an A record, all the CNAME records pointed to that A record automatically follow the new IP. The most common CNAMEs are subdomains “www” and “ftp.”
Note: If all of your web services (Web, FTP, etc.) are on the same server, pointing to the A record works. If you have different servers for services, you need to point the particular services to the proper IP addresses.
A MX record is the feature in the DNS that specifies the mail server to direct emails to on behalf of your domain. If there are multiple mail servers available, it helps to prioritize them. Think of this as the mail room for your domain.
How does DNS know which IP address to use?
Domain names point to nameservers to locate their zone files — to do this, a domain name must point to the nameserver holding its specific zone file. Going back to the file cabinet analogy — a person (DNS) would have to know which file cabinet (nameserver) the folder (zone file) is in to access the DNS (paper.)
Does anyone use file cabinets anymore … Bueller … Bueller?
How do you know which nameserver to use?
When you register a domain name with GoDaddy — it’s automatic. We park the domain name and set its nameserver to our parking servers. If you activate the domain name or make changes to your website’s hosting, your hosting company provides the nameserver names or IP addresses where your domain name’s zone file is located. You can use this information to update your domain name settings at your registrar. Once you’ve updated your nameservers or IP address, it can take 24 to 48 hours for the new information to propagate through the Internet — and then visitors can reach your website using your domain name.
During your next meeting or casual Sunday brunch, when someone else asks, “What is the domain name system?” you can answer with the confidence of a DNS wiz.