When we talk about managed services, it is difficult to not mention DNS, specially when they are so closely connected in the managing IT networks system. In managed services, DNS handling becomes essential for keeping websites and services running smoothly. It ensures that domain names are set up correctly, leading users to the right places online.
While there are high chances that your managed service providers might also be specialists in handling DNS setups, monitoring, and problem-solving, it would help to understand the technology outside of the ecosystem.
The Domain Name System (DNS) is like a phonebook for the Internet. Instead of remembering long strings of numbers, humans access websites with easy-to-remember domain names like nytimes.com or espn.com. Web browsers communicate using Internet Protocol (IP) addresses. DNS helps by translating these domain names into IP addresses so that browsers can locate the websites. Every device that is connected to the Internet has its own unique IP address, which is used by other devices to locate it.
DNS servers make it easier for us by removing the need to remember complicated IP addresses like 192.168.1.1 (in IPv4) or the more complex alphanumeric IP addresses such as 2400:cb00:2048:1::c629:d7a2 (in IPv6).
How does DNS work?
Now that we have looked into what is DNS, it’s time to look into the way it works. When you want to visit a website, your computer first needs to figure out the IP address of the server that hosts that site. This process is known as DNS resolution. Just like how a street address helps you find a specific house, an IP address helps your device locate the right server on the internet.
So, when you type in a website like “www.example.com,” your computer translates that into the corresponding IP address, like “192.168.1.1,” so that it can load the webpage you’re looking for.
Here’s how the process looks like.
When a user enters a web address or domain name into a browser, the browser sends a message called a recursive DNS query to the network to determine the IP or network address associated with the domain. The query is sent to a recursive DNS server, also known as a recursive resolver, typically controlled by the internet service provider (ISP). If the resolver has the address, it will provide it to the user, allowing the webpage to load.
When a recursive DNS server is unable to find an answer, it will reach out to a sequence of other servers in this specific order: DNS root name servers, top-level domain (TLD) name servers, and authoritative name servers. These three types of servers collaborate to keep redirecting until they discover a DNS record with the requested IP address. Once they obtain this information, they send it back to the recursive DNS server, allowing the user’s desired webpage to load. DNS root name servers and TLD servers mainly focus on redirecting queries and seldom offer the resolution directly.
The three servers collaborate and keep sending requests until they find a DNS record with the requested IP address. Once they locate it, they pass on the information to the recursive DNS server which then loads the webpage the user is trying to access. DNS root name servers and TLD servers mainly redirect queries and do not often provide the resolution directly.
The DNS components
The Domain Name System (DNS) is made up of key components that cooperate to translate human-readable domain names into IP addresses, ensuring efficient and accurate resolution of DNS queries.
The main components of DNS, which also indirectly answers a portion of what are managed services include:
- DNS Client: This software component on a user’s device or application starts DNS queries by sending them to DNS resolvers for the IP address linked to a domain name.
- DNS Resolver: This component receives DNS queries from clients and locates the relevant IP address.
- Root DNS Servers: The Root DNS Servers are the top-level servers in the hierarchy of the DNS system. There are a limited number of servers globally that offer details about the authoritative DNS servers for TLDs such as .com, .org, and country-code TLDs like .uk, .jp, etc.
- Top-Level Domain (TLD) DNS Servers: These servers handle the DNS records for particular TLDs like .com, .org, .net. They provide information about the authoritative DNS servers for second-level domains under their TLD.
- DNS Records are like virtual address books that tell your computer where to find websites. They contain important information that connects domain names (like google.com) to their corresponding IP addresses. Common types of DNS records include A, AAAA, MX, CNAME, TXT, and NS.
- A DNS Zone is like a designated neighborhood within the internet where a specific organization or company has control. It holds all the important DNS records for a domain and its subdomains, helping to route internet traffic efficiently.
- TTL, or Time-to-Live, is a setting that determines how long a DNS record can be stored in a resolver’s cache before needing to be refreshed from the main DNS servers. It helps keep internet traffic running smoothly by ensuring that information stays up-to-date.
What does a DNS structure look like?
The website address is typically found in a URL. A website address consists of different segments, known as labels. The website hierarchy is followed from right to left, with each part representing a division. The top-level domain (TLD) is located after the dot in the website address.
Some examples of top-level domains are .com, .org, and .edu, although there are numerous others. Certain TLDs may indicate a specific country or region, like .us for the United States or .ca for Canada.
In a URL, the labels on the left side of the top-level domain (TLD) represent additional subdomains of the domain located to the right. For instance, in the web address www.forbes.com, “forbes” is a subdomain of .com, while “www.” is a subdomain of forbes.com.
How does DNS improve website performance?
Servers can store A records, or IP addresses, obtained from DNS queries for a certain period of time. This caching enhances efficiency, allowing servers to quickly respond when another request for the same IP address is made.
For instance, if all employees in an office need to watch the same training video on a specific website on the same day, the local DNS server only needs to resolve the name once.
After that, it can fulfill all subsequent requests from its cache. The duration for which the record is stored — also called time to live (TTL) — is determined by administrators and varies based on different factors.
Let’s say everyone in an office needs to watch a training video on a specific website on the same day. The local DNS server would only have to look up the website’s name once, and then it can quickly serve the video to all the other users from its cache. The duration for which this information is stored, also known as the time to live (TTL), is determined by administrators and can vary based on different factors. Longer TTLs help reduce the strain on servers, while shorter ones ensure the most up-to-date responses.
In conclusion, understanding the basics of DNS is fundamental for anyone navigating the vast networking and internet space. DNS serves as the backbone of the internet, translating user-friendly domain names into IP addresses that computers use to communicate.
This system facilitates seamless web browsing, email communication, and various online services we rely on daily. By grasping DNS concepts we hope you have gained insights into how data travels across the internet and how to troubleshoot common networking issues.
With a solid understanding of DNS basics, you can now be better equipped to optimize their network performance, enhance security measures, and ensure reliable connectivity in the digital age.
