The Domain Name System (DNS) is among the central foundations of the Internet. In the most basic sense, it’s a directory composed of names with matching numbers called Internet Protocol (IP) addresses that computer systems utilize for communicating with each other. Think of it as a phone book or the contact list of your smartphone that matches your contacts with their contact information, but in a much more massive scale. This is a key networking concept that you should brush up on when studying your guide for CompTIA Network Plus N10-007 certification exams, especially if you want to pass.
How Does DNS Function?
The DNS directory list that pairs names to numbers aren’t merely contained in a specific place on the Internet. Similar to the Internet itself, it’s distributed worldwide and located on multiple domain name servers capable of communicating with each other regularly to give redundancies and updates.
Every single named website is paired with multiple IP addresses. Some websites even have hundreds of IP addresses that match only one domain name. For instance, the server that your computer system reaches for www.abcd.com won’t be the same server that another individual (who’s trying to reach the same website) would get when they type www.abcd.com into the browser.
DNS Adds Robust Efficiency
The distributed property of the DNA directory is vital for efficiency. Thinking about this, it would surely take an immensely long time for you to obtain a response when searching for a website if the DNS directory is only located in one location and shared between all Internet users, searching for the same information simultaneously. This is why the DNS directory is stored in multiple servers and locally cached on client computer systems.
Look at it this way: Let’s say that you access abcd.com multiple times daily. Rather than your computer system trying to query the site’s DNS name server to acquire the site’s IP address each time, that specific information is stored in your system so it doesn’t need to reach the DNS server all the time. Likewise, additional caching could happen on routers utilized for connecting to the Internet, and on the servers of the Internet Service Provider (ISP) of the Internet user.
What You Need to Keep in Mind
DNS is essentially the Internet’s contact list or phonebook that maintains a domain name directory it translates to IP addresses. Its function is extremely important since while Internet users could easily remember domain names, machines or computer systems access sites through the sites’ IP addresses.
For example, DNS pairs abcd.com with an IP address like 72.18.121.25 that computers could use for identifying each other. Network devices and computer systems then utilize IP addresses for routing requests to websites that Internet users are attempting to access. Think of it as dialing phone numbers on your phone to reach a contact you want to talk to.
Because of DNS, you won’t need to keep a directory of IP addresses because you could simply connect via a DNS server that manages the directory that in turn matches domain names to specific IP addresses.