The Domain Name System (DNS) is often compared to a phonebook, and there are a lot of similarities. It is another type of database. DNS is a global system that we all use on a daily basis when we want to access any website. It contains and distributes information about domain names and their corresponding IP addresses. This way, when we type a simple domain name, our browsers or application will use the DNS to search for its IP address and connect us. The DNS is divided into domains from different levels, and it is managed through DNS zones that are decentralized. An administrator of a higher level can delegate a zone to another under it. For example, when you get a domain name (secondary-level domain like yoursite.com), the higher level .com (TLD) can delegate you the right to manage the zone yoursite.com. You can further delegate responsibility for all subdomains like mail.yoursite.com, ftp.yoursite.com, etc. To manage domain names, you add DNS records, which are a set of instructions related to your domains, hosts, services, and more.

Domain Name System explained

List of DNS terms

Here you have the most important DNS terms that you will need to manage your domain name. First, you can learn the basics of DNS, and later you can expand your knowledge with larger articles that go into greater details on topics like DNS records, DNS features, and processes. 

Domain Name

It’s an identifier of a host, a text line, that servers for mapping to an IP address (a line of numbers like: 46.166.142.62) for easy access to a website. By now, you have typed a lot of different domain names in the URL bar of your browser to reach different websites. Example: cloudns.net

Machines have always searched websites through their IP address. Numbers are the best way for machines to understand each other. But numbers are hard to be remembered by humans. That’s why domain names were created. To have a friendly choice for humans to reach the websites they look for.

IP Address

An Internet Protocol address is another host identifier that is created of a line of numbers divided into groups by periods. Example: 46.166.142.62. IP addresses are needed so devices can connect to networks and communicate using the Internet Protocol (IP).

The set of numbers on every public IP address is mathematically generated and allocated by the Internet Assigned Numbers Authority (IANA). An entity of the Internet Corporation for Assigned Names and Numbers (ICANN).

Basically, IP addresses allow the identification, location, and communication of hosts on a network. Every device uses a unique IP address. This way, the Internet and networks, in general, can distinguish all the websites, routers, connected computers.

Many IPv4 addresses are still in use, but the latest standard IPv6 is growing in popularity.

TLD (Top-level Domain)

Domain names have a hierarchy structure. The top-level domain is one of its parts, and it’s located, reading from right to left, just after the final dot for the root and before the secondary-level domain name. Examples: .com, .gov, .uk, .ru, etc.

Initially, TLDs were created to organize domain names by their purpose, geographical location, field, operation radius. By only reading this part of a domain name, users could also know if a website they visited belonged to a commercial, government, non-profit organization, operating regionally, locally, internationally, and so on.

In the beginning, this use was more strict. In 2010, the Internet Corporation for Assigned Names and Numbers (ICANN) accepted the creation of new, generic, trademark TLDs. Now, TLDs are chosen to obey Marketing objectives too.

FQDN (Fully Qualified Domain Name)

It’s the most complete domain name that hosts can have. It points to the exact location of a domain name in the domain name system (DNS) tree hierarchy. This is expressed through the three parts that shape every domain name: hostname, second-level domain name, and top-level domain name (TLD). Following this structure, here you have an example: www.cloudns.net.

Anycast DNS

Anycast DNS is a traffic routing method where the same IP address is used for multiple nameservers located in different locations. Usually, there are many locations (points of presence) – at least 20 for a well-sized DNS provider. Having a large number of servers makes Anycast DNS resistant to DNS attacks and provides redundancy in general. 

When a client request a domain, the router will direct its request to the nearest nameserver. This will reduce the latency and offer a better experience for the clients.

Dynamic DNS

Dynamic DNS, also known as DDNS, is an automatic method of updating nameservers. The most common use case is to update IP addresses that are contained in A records (IPv4) or AAAA records (IPv6) when a change has occurred. It is particularly useful for CCTV cameras or remote services because with Dynamic DNS, you don’t need to pay for static IP addresses. The IP addresses will change over time, but they will be updated, and you won’t experience problems. After the initial setup process, you don’t need to interact with the settings, and it will continue to function.

DNSSEC

DNSSEC is a security extension that has the goal to protect DNS communication and stop DNS spoofing. It encrypts the DNS communication with a combination of private and public keys. One that the zone administrator uses to sign it and the other for authentication of the origin of the data. What makes it a good protective mechanism is that it is a complete chain of trust. Starting from the root zone down to the TLD zone, the domain zone, and subdomains, each zone above will have the key for the next one. It adds security to the fast DNS process without a significant slowdown.

DNS Server (types)

There are different DNS servers, and each has specific functionality.

Root server. It belongs to the highest level of DNS servers. It’s the authoritative name server for a specific DNS root zone. It points to the TLD of the requested domain name.

TLD server. It’s responsible of specific TLDs (.com, .gov, .uk, .net, etc.). It will point to the exact, authoritative name server that can provide the IP address for the requested domain name.

Recursive DNS server. The server takes the user’s DNS request and looks for the IP address or other information needed for the requested domain name. It will communicate with all the other DNS servers in the hierarchy for getting this information.

Authoritative DNS server. It contains all the DNS records for the zone it’s in charge of. It answers the requests that recursive DNS servers have by providing the corresponding A or AAAA record and the IP address of the requested domain or another DNS record.

Primary authoritative DNS servers. They answer DNS requests, and they store the original zone file. Therefore, DNS records’ modifications can only be made on these servers. 

Secondary authoritative DNS servers. They also respond to DNS requests, but what they store is a copy of the zone file. This copy is not editable at all, only readable. 

DNS Zone

The DNS system has a structure that looks like an inverted tree. It is divided into domain names on different levels. The highest level is the root, after many TLDs, secondary-level domains, and later multiple levels of subdomains. To administrate those domain names, there are DNS zones on each level. The DNS zones are partitions of the Domain Name Space that contain DNS zone files with DNS records for managing. A DNS zone administrator can add or remove DNS records inside the Primary DNS zone.

DNS records

DNS records are simple files that contain text with instructions related to the domain name they belong to. They can link domain names to IP addresses, add instructions for email servers, point to specific services, and much more. The DNS records are hosted inside a host file in a DNS zone. The zone is located inside an authoritative nameserver.

There are many types of DNS records, but the most popular ones are:

A record – Links a domain name to an IP address. 

CNAME record – Forwards subdomains to the domain name.

MX record – Indicates the email servers that should receive emails for the domain name.

TXT record – Multiple verifications and authentication purposes.

NS record – Shows the nameservers for the domain name.

SOA record – Start of authority.

SRV record – Links services to port numbers.

PTR record – The Pointer record links an IP address to a domain name.

The Importance of DNS Terminology

Understanding DNS terminology is crucial for various reasons, including the following:

• Efficient Troubleshooting: Solid knowledge of DNS terms allows IT professionals to diagnose and resolve technical issues more efficiently. Identifying the root cause of problems, such as domain resolution failures or misconfigured DNS records, becomes significantly easier and faster.
• Enhanced Security: Cybersecurity is a top priority nowadays. Therefore, it is best for professionals to understand DNS terminology in order to detect and respond to potential threats. Understanding terms like DNSSEC, DNS spoofing, cache poisoning, and DDoS attacks helps strengthen the security of networks and web services.
• Performance Optimization: Website owners and developers can benefit from understanding DNS terminology to optimize the performance of their online presence. Fine-tuning DNS settings, minimizing TTL values, and ensuring proper DNS record configurations contribute to faster and more reliable website performance.
• Effective Communication: Clear communication within IT teams, especially between developers, network administrators, and support teams, is crucial, especially when they need to communicate complex technical issues. A common understanding of DNS terms allows effective communication and collaboration within teams.
• Domain Management: Individuals and organizations involved in registering and managing domains must be familiar with DNS terminology to make informed decisions. Knowledge of terms like TLDs, registrars, and DNS hosting providers empowers domain owners to navigate the complexities of the domain ecosystem.

Conclusion

This list of basic DNS terms you should know is a good start for exploring the DNS. If you want to learn even more, follow our blog, in which we regularly post new extended articles. Also, don’t miss our Wiki page and YouTube channel.

The post Basic DNS terms you should know (List + Infographic) appeared first on ClouDNS Blog.

What is FQDN?

The popular acronym FQDN stands for Fully Qualified Domain Name. It represents the fullest possible domain name of a host or a computer on the internet. In addition, it could be related to a website or to a server. 

As you probably know, the Domain Name System (DNS) is decentralized, and it is built in a very precise hierarchical order. The Root is the beginning and above everything else, and one level below is the Top-Level Domain (TLD). The following component in the hierarchical order is the domain, and finally, the last important element is the precise hostname.

• FQDN Syntax

Here you can see the syntax of it:

[hostname].[domain].[tld]

It can also include a subdomain. Yet, you should know that the subdomain is not the hostname. It is just a part of the domain. 

• FQDN Example

Let’s see an example of FQDN using cloudns.net. We read it from right to left.

www.cloudns.net

First is “.net“, which is the Top-Level Domain (TLD). Then it follows the domain name “cloudns“, and the last is the hostname “www.“. 

The hostname can show a specific service or protocol for the domain like “mail” or “ftp”.

The FQDN serves to show the exact location of an object inside the DNS hierarchy.

Structure and elements of FQDN

The Fully Qualified Domain Name (FQDN) actually has a very simple and easy-to-understand structure and three main elements. So, let’s explain a little bit more about them:

TLD (Top-Level Domain): It is shown with all of the standard extensions that are located at the very end of an FQDN. They usually are very short, and their length is just 2 or 3 letters. Some popular examples are .com, .edu, .uk, etc. Of course, in the present days, you can find TLDs that are a little bit longer than that. For instance, there are .systems, .company, etc.

Domain: It stands exactly after the Top Level Domain (TLD) and is very well-known, and regular users are familiar with it. Here is a simple illustration – example.com.

Hostname: You can also identify it with ease. It is represented by the symbols at the very beginning of the Fully Qualified Domain Name (FQDN). Here a widespread and familiar example is www in www.example.com. Some domain owners could create different hostnames based on the need of their domain name. Each of them is going to be related to the domain. Several examples of such different hostnames are:

• www.example.com
• ftp.example.com
• mail.example.com

What is PQDN?

The short acronym PQDN stands for Partially Qualified Domain Name and it simply represents an FQDN (Fully Qualified Domain Name) with a missing part. It does not include all of the elements that provide the precise position on the DNS hierarchy. It is just a part of the complete domain name. 

To make things more simple, let’s use the ClouDNS domain name again for an illustration. The PQDN is, for example, “cloudns.net“. In this one, we don’t have the host “www.“.

Many users use PQDN daily without even knowing it. The reason for that is simple. PQDN is more accessible and easy to use. In addition, it is shorter, which makes daily searches quicker and easier.

If you are searching for a fast and secure DNS service – the best choice is the Anycast DNS!

How to make a FQDN lookup?

You can perform an FQDN lookup on your computer with any of the popular operating systems (OS).

Windows 10

Here is how to see the FQDN on a Windows 10 device:

1. Click on the Start menu, type “Control Panel,” and click it. 
2. Inside the Control Panel, find “System” and open it. 
3. Inside the System, look for “Device specifications” and search for the “Full Computer Name.” 
4. There is the FQDN. 

macOS 

If you are using macOS, follow these next steps to find the FQDN.

1. Open the Terminal application.
2. Inside, type the following command: “hostname -f” and press the Enter button. The option “-f” means full. 
3. You will see the FQDN. 

Linux 

If you are a Linux user, you can find the FQDN similar to the macOS.

1. Open the Terminal application. 
2. Inside, type the following command: “hostname -A” and press the Enter button.
3. You will see the FQDN. 

Why do you need FQDN?

Here are some of the main cases when FQDN comes in hand:

• You will need FQDN to make a device accessible on the internet. You will use it to configure your DNS and get an IP address.

• Another use case is when you want to get an SSL certificate. Today, almost every site has one, and you need to provide the FQDN to obtain it.

• Remote Access. The DNS server will perform a lookup in its registers and resolve the FQDN to the correspondent IP address.

• Access a protocol or a service. If you want to use a FTP for example, you will need the Fully Qualified Domain Name or IP. Also, for setting up email for specific applications, you will need it.
• Network management: FQDNs are crucial in large networks for segmenting and managing different zones efficiently, ensuring secure and organized traffic flow.
• API access: In cloud computing and web services, FQDNs are key for identifying and accessing API endpoints, enabling smooth communication between software systems.

FQDN vs URL: Are they the same thing?

In the technical realm of internet architecture, the terms Fully Qualified Domain Name (FQDN) and Uniform Resource Locator (URL) are often conflated, yet they serve distinct roles. An FQDN represents a complete and precise domain name, providing an exact location in the Domain Name System (DNS) hierarchy. This includes the top-level domain and all subordinate levels. In contrast, a URL is a comprehensive descriptor used to locate a specific resource on the internet. It includes the protocol (e.g., HTTP/HTTPS), the FQDN, and additional components like resource path and query parameters. While an FQDN is a critical part of a URL, delineating the domain aspect, a URL extends this concept to encompass the full path necessary for accessing a particular internet resource. Understanding these nuances is crucial for professionals dealing with web development, networking, and IT infrastructure.

Conclusion

In summary, Fully Qualified Domain Names are an essential aspect of internet navigation and domain management. They provide a detailed and specific way of identifying and locating computers or services within the vast network of the internet, ensuring precise and reliable connectivity. Understanding FQDNs is crucial for effective domain setup and management, making it a fundamental concept for anyone working with or interested in the digital domain space.

The post What is FQDN? What does FQDN do? appeared first on ClouDNS Blog.