DNS: All you need to know about it!
Table of contents
DNS, or the Domain Name System, is often a very difficult part of learning how to configure websites and servers. Understanding how DNS works will help you diagnose problems with configuring access to your websites and will allow you to broaden your understanding of what's going on behind the scenes.
Before we jump into setting up your own servers to resolve your domain or setting up our domains in the control panel, let's go over some basic concepts about how all of this actually works.
ICANN plays a similar administrative role with the IP addresses used by computers as it does with the domain names used by humans. In the same way that you cannot have two domain names the same (otherwise you never know where you would end up), for the same reason it is also not possible for there to be two IP addresses the same.
Again, ICANN does not run the system, but it does help co-ordinate how IP addresses are supplied to avoid repetition or clashes. ICANN is also the central repository for IP addresses, from which ranges are supplied to regional registries who in turn distribute them to network providers..
At this point you must be thinking:
Okay, so DNS system offers sort of a hierarchy, right?
Indeed, it is a hierarchy and that leads me to this point, root-server are the top of that hierarchy.
These servers are controlled by various organizations and are delegated authority by ICANN (Internet Corporation for Assigned Names and Numbers).
There are currently 13 root servers in operation. When requests are made for a certain root server, the request will be routed to the nearest mirror of that root server.
The interesting thing about this set up is that each of the mirrors for a single root server share the same IP address.
What do these root servers do?
Root servers handle requests for information about Top-Level domains. So if a request comes in for something a lower-level name server cannot resolve, a query is made to the root server for the domain.
The requester then sends a new request to the IP address (given to it by the root server) that is responsible for the top-level domain of the request.
So, to continue our example, it would send a request to the name server responsible for knowing about "org" domains to see if it knows where "www.wikipedia.org" is located.
What if we misspell the URL?
The requester will look for "www.wikipdia.org" in its zone files. It will not find this record in its files, however, it will find a record listing the IP address of the name server responsible for "wikipedia.org".
TLDs are classifies on three groups:
The point of this post was to clarify all about domains and give options.
Here is a list of website where you can acquire domains:
What do you think? Will you acquire one?
Introduction
DNS, or the Domain Name System, is often a very difficult part of learning how to configure websites and servers. Understanding how DNS works will help you diagnose problems with configuring access to your websites and will allow you to broaden your understanding of what's going on behind the scenes.
Before we jump into setting up your own servers to resolve your domain or setting up our domains in the control panel, let's go over some basic concepts about how all of this actually works.
DNS
Let's start easy:
Domain name system:
The domain name system, more commonly known as "DNS" is the networking system in place that allows us to resolve human-friendly names to unique addresses.
Domain name:
A domain name is the human-friendly name that we are used to associating with an internet resource.
IP address:
An IP address is what we call a network addressable location. Each IP address must be unique within its network.
Top-Level domain:
The top-level domain is the furthest portion to the right (as separated by a dot).
We'll get more on that later.
Hosts:
Within a domain, the domain owner can define individual hosts, which refer to separate computers or services accessible through a domain.
Fully qualified domain name:
A FQDN is an absolute name that specifies its location in relation to the absolute root of the domain name system.
Name server:
A name server is a computer designated to translate domain names into IP addresses.
Zone file:
A zone file is a simple text file that contains the mappings between domain names and IP addresses.
Records:
Within a zone file, records are kept. In its simplest form, a record is basically a single mapping between a resource and a name.
Domain name system:
The domain name system, more commonly known as "DNS" is the networking system in place that allows us to resolve human-friendly names to unique addresses.
Domain name:
A domain name is the human-friendly name that we are used to associating with an internet resource.
IP address:
An IP address is what we call a network addressable location. Each IP address must be unique within its network.
Top-Level domain:
The top-level domain is the furthest portion to the right (as separated by a dot).
We'll get more on that later.
Hosts:
Within a domain, the domain owner can define individual hosts, which refer to separate computers or services accessible through a domain.
Fully qualified domain name:
A FQDN is an absolute name that specifies its location in relation to the absolute root of the domain name system.
Name server:
A name server is a computer designated to translate domain names into IP addresses.
Zone file:
A zone file is a simple text file that contains the mappings between domain names and IP addresses.
Records:
Within a zone file, records are kept. In its simplest form, a record is basically a single mapping between a resource and a name.
ICANN
ICANN plays a similar administrative role with the IP addresses used by computers as it does with the domain names used by humans. In the same way that you cannot have two domain names the same (otherwise you never know where you would end up), for the same reason it is also not possible for there to be two IP addresses the same.
Again, ICANN does not run the system, but it does help co-ordinate how IP addresses are supplied to avoid repetition or clashes. ICANN is also the central repository for IP addresses, from which ranges are supplied to regional registries who in turn distribute them to network providers..
Root-Server
At this point you must be thinking:
Okay, so DNS system offers sort of a hierarchy, right?
Indeed, it is a hierarchy and that leads me to this point, root-server are the top of that hierarchy.
These servers are controlled by various organizations and are delegated authority by ICANN (Internet Corporation for Assigned Names and Numbers).
There are currently 13 root servers in operation. When requests are made for a certain root server, the request will be routed to the nearest mirror of that root server.
The interesting thing about this set up is that each of the mirrors for a single root server share the same IP address.
What do these root servers do?
Root servers handle requests for information about Top-Level domains. So if a request comes in for something a lower-level name server cannot resolve, a query is made to the root server for the domain.
TLDs
The requester then sends a new request to the IP address (given to it by the root server) that is responsible for the top-level domain of the request.
So, to continue our example, it would send a request to the name server responsible for knowing about "org" domains to see if it knows where "www.wikipedia.org" is located.
What if we misspell the URL?
The requester will look for "www.wikipdia.org" in its zone files. It will not find this record in its files, however, it will find a record listing the IP address of the name server responsible for "wikipedia.org".
TLDs are classifies on three groups:
- Generics(.com, .org).
- Geographics(.es, .uk).
- Infrastructure, although this last one, was created in 1985 and deprecated long time ago.
All you need to know about domain registration
The point of this post was to clarify all about domains and give options.
Here is a list of website where you can acquire domains:
What do you think? Will you acquire one?
Thank you for reading my amateur tutorial and I hope we'll keep improving together!
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