The domain name system (DNS) connects URLs with their IP address. With DNS, it’s possible to type words instead of a string of numbers into a browser, allowing people to search for websites and send emails using familiar names. When you search for a domain name in a browser, it sends a query over the internet to match the domain with its corresponding IP. Once located, it uses the IP to retrieve the website’s content. Most impressively, this whole process takes just milliseconds.
It might seem like magic when you go online shopping, video chat across continents, and stream videos or music to your phone, but this is all thanks to the sophisticated engineering achievement that is the domain name system (DNS). DNS is a powerful network that keeps billions of internet users and over 300 million domain names connected.
The DNS underpins the internet we use every day. This transparent network runs in the background whenever you send an email, or load a website. DNS is often likened to the internet’s version of a telephone book. To call someone, you must first find their telephone number. To do so you look up a contact name, similary, DNS converts email addresses and websites humans read into computer-readable, numerical IP addresses.
What does DNS Mean
The DNS goes by many names, including name server, domain name system server, and nameserver. Regardless of which name is used, all describe the process of making domain names alphabetical. DNS also refers to the hierarchical system used to search through the network of millions of IP addresses, to locate the exact IP of your desired website.
How DNS Works
Everything that connects to the internet – websites, tablets, laptops, mobile phones, Google Home, internet thermostats, and refrigerators has an IP address. An internet protocol address by its full name is a unique string of numbers that identifies each digital device to communicate via the world wide web.
Thanks to DNS, there is no need to maintain an address book of IP addresses. Every time you use a domain name, the DNS service locates the website and translates the name into its corresponding IP address.
- IP addresses help locate a computer on the internet and relay the information traveling between computers. As soon as you type a domain name, for example, Amazon.com into your browser, your browser, and computer check if one of them has the domains related IP address in their memory.
- If Amazon.com isn’t in your computer’s local memory (cached memory), it expands the search out to the internet where it queries the DNS to determine if the domain exists in their DNS database.
- Once the DNS server finds the domain name Amazon.com, the server returns the domain name, and it’s IPS address to the requesting DNS server, along down the line until it arrives back at your computer.
- Once the IP address has reached your computer, your browser finds it on the internet. Next up, it communicate with the domain name hosted to request any associated files. The host server returns the files which display Amazon.com in your web browser.
DNS Operations
The DNS operates a client/ server network system performing the following operations:
- Send requests to and receives responses from DNS servers. This is known as forward DNS lookups.
- Besides forward lookups, the DNS can request reverse lookups that query an IP to determine the associated domain name.
- Find the correct servers to deliver email.
How is the DNS Organized?
The internet is set up of a large network of computers located around the world. DNS is a hierarchical system that works by crawling through information on a system of linked DNS servers to determine the location of a particular domain names server.
- Third-Level Domain – Also known as the subdomain. The most common subdomain is www. But they can take many forms, such as books.google.com.
- Second-Level Domain – This is the often the name of the website and the unique part of the domain name, appearing to the immediate left of the TLD. For example, the second-level domain in the URL www.washahost.com is WashaHost.
- Top-Level Domain – Is the furthest point to the right of the domain. The most common TLD is .com.
- IP Address – An Internet Protocol address is an addressable location on the internet. Each IP is unique with its network.
How are Domains Mapped to IP Addresses
The process is called DNS resolution and plays out over eight steps:
- When you type a domain or full web address into your browser, your browser sends a message to the network asking for help.
- Your computer contacts a machine known as a recursive resolver to locate the previously cached IP address.
- If the recursive resolver fails to find the address, they query the DNS root name servers.
- The root name servers direct your ISP through the DNS hierarchy.
- Each top-level domain in the DNS has its own set of nameservers.
- Your ISP queries the referred DNS name servers for the applicable IP address.
- Your ISP provider’s resolver retrieves the A record from the authoritative name servers and stores it in its cache.
- The last step sees your ISP’s recursive servers deliver the A record to your computer.
DNS Configuration
Most sites have a server which takes care of its DNS. In most cases, two DNS servers are configured on your router and/ your computer to connect your ISP via DHCP. You may configure two in the case the primary server fails.
Speed is an essential part of SEO since the time to connect to a web page is a ranking factor for Google. Experts recommend opting for reliable hosting with good speed and uptime capabilities.
DNS hosting
Many domain name registrars offer hosting with domain registration, and there are free and premium DNS hosting services available.
- Free DNS: Try free DNS hosting for your website and decide later whether you need to upgrade to premium or not.
- Premium DNS accounts: Premium hosting provides quicker response times to your visitors, unfailing access, maximum uptime and more powerful security measures.
DNS Propagation
This process, known as DNS propagation can take up to 72 hours to take effect, during which the ISP updates their caches with the new DNS information for your domain.
Domain Name Elements
- A Record: Directs your domain name to an individual server through its IP address.
- AAAA Record: Lets you direct your domain to a 128-bit Ipv6 address.
- CNAME: Used to redirect your domain or subdomain to the IP address of the destination hostname.
- MX Record: Used to direct mail to the appropriate mail server.
- NS Record: Lets you delegate a subdomain to a nameserver associated with the domain.
