How Does DNS Propagation Work?
We’ve all known what DNS is, but when asked about how it works we barely know anything about it. Therefore we thought of adding this information for you to understand it.
Many-a-times we see customers complaining about their sites not visible despite having registered it and hosting the site over a web server. This is a grey area where due to lack of understanding about DNS functionality, people tend to develop a feeling of distrust for a company. But as a matter of fact, it’s because of the propagation time taken by the DNS servers, the site fails to displayed instantly.
Though we agree that this can at-times be frustrating, but this is something beyond anyone’s control. You’d agree to this as we go through the process of DNS propagation and understand its functionality.
So to quickly revise, DNS is an abbreviated term for Domain Name Server as we all know is a/are machine(s) that carries out multiple complex computation processes.
Let’s see what those processes are. But before that, inorder to get a better understanding of things we’d need to understand certain other areas that support the DNS propagation process, which is :
- IP Addresses
- Service Providers
- Domain Names
- Domain Name Registrars
- The Propagation Process
We all have heard and known about IP addresses since a long time. We usually get to hear that the pool of IPv4 has almost gotten exhausted and new machines are made IPv6 compatible, etc. Well these IP addresses are something that’s used by computers to identify and communicate amongst each other.
The Internet Assigned Numbers Authority (IANA) manages the IP address space allocations globally and delegates five regional Internet registries (RIRs) to allocate IP address blocks to local Internet registries (Internet service providers) and other entities.
A large volume of transactions of IP address allocation and de-allocation happens every second across the globe, which is managed by the service providers.
Service Providers popularly known as ISPs manage the allocation of IP addresses to the specific equipments to enable connectivity to the Internet. The second in the niche of service providers that deal with management and allocation of IP are the web hosting service providers. Without an ISP you wouldn’t have access to the Internet cause of which would be the failure to send emails, browse the internet, download or upload stuffs etc. When you connect a device to the internet, the ISP system automatically allocates an IP address to it. Thereafter until you disconnect the device, it’d be identified by that IP.
Whereas, when you are connected to the internet and carry out transaction of emails, surf websites, offers, book tickets etc., in the back-end the website is basically hosted over a web server to which your browser connects to and tries to retrieve information. This web server too has a unique IP address to which your device communicates with. This IP is assigned by the webhosting company.
So if we try understand the whole process of web surfing from an overview, we realize that to do so we need a computing device such as smartphone, tablet, laptop, PC etc. through which we need to connect to the Internet and user a web browser such as Firefox, Chrome, IE, Opera etc. to search/use the web for sites.
Basically when you access a website, the device sends a request to the server that holds the website files. Though while the request is being sent, it goes through different routers, network switches, gateways, ISPs etc. before reaching the destination server that holds the website and travels back to your device. Now all this happens smoothly due to the known IP allocation of your device and the server to each other.
To make it simpler to understand from a process perspective, it is an IP (your device) which requests for a webpage hosted by a server (which has its own unique IP too). The two devices in a network identify each other with the IPs hence becomes a flawless process.
This was about the IP address and the service providers role. Now the actual part of the explanation about the DNS propagation process starts with the domain names.
Domain name is nothing but the website address which we typically add in the web browser search bar, for example :
A domain name is the one that we humans refer to a website over the web, we get to read, share, buy services, products, knowledge etc. But computing machines do not understand a website by its name but rather the IP address.
So how do the computing machines refer or understand these numbers i.e. IP address and relate it with a domain name, that’s the question. This is where the domain name registrar comes into role.
Domain Name Registrar
Domain names are controlled by a company referred as the Domain Name Registrar. It’s through them that you can register a domain name of your choice (provided it isn’t already registered by anyone else).
It is from this point that the role of DNS begins.
DNS – Domain Name Servers
To define it in simple terms, DNS is a software program which is hosted and run from high configuration dedicated machines capable of handling multiple computational processes at any point of time.
Primarily these servers are responsible to carry out two functions:
1) To translate domain names into IP addresses and
2) To act as an authority for domain names
So, when your computing device requests for a information available as a particular webpage under a domain name which has an IP address, it asks the DNS server. Only after the DNS server gives the details to the requesting machine, the webpage gets served.
No matter which or whose website it is, it is important that its details are updated with the DNS server. Typically there are two DNS servers that act as an authority for any domain name also referred as the ‘A’ records.
There are thousands of DNS servers across the world, which act as the databases containing information about a domain name. Now, it doesn’t mean that information about a domain name is available on each DNS server. Some DNS servers would have records of domain names while the others would serve the role of lookup services for requester machines. Though, you may also find few servers that carry-out both the roles simultaneously.
Information such as the DNS records, A records etc. are stored by these servers, this is all that you need to remember for now.
The Process of DNS Propagation
As we’ve learn’t above, the domain name registrar is the one who approves, publishes and manages a domain name. Upon publishing, its details are recorded in a directory which then broadcasts to the primary DNS servers across the globe. After which it is further shared with the secondary, tertiary and other DNS servers.
This is something which is referred as the propagation. And to get the details for a domain updated globally where each DNS server knows about the newly added information; it can take upto 72 hours.
This new information may be about a newly registered domain name OR any changes made to a domain name OR about the change in the domain name registrar.
After the DNS propagation process gets completed, you can be rest assured about your website accessibility by anyone from anywhere.
But many-a-times customers do tend to see inconsistency upon accessing a domain name. This might be due to the failure of DNS to retrieve information from its database. Most of the times because the customer isn’t aware of this process, they tend to put blame on the hosting provider assuming about a faulty server infrastructure. Without the host doing anything and after waiting for sometime, the sites starts resolving flawlessly.
We hope that after reading all this you’d have understood the whole process well. Though if you haven’t and need to get more information, please post your comment below this article and we’ll make it a point to respond to you. OR you may choose to raise your queries over Webhosting UK community forums.