Interesting Information About DNS Servers

Before DNS servers came into existence, a website could only be identified by machines through its host name. All of these host names were saved in one large file known as the hosts.txt. However, this method of managing host names became hard to maintain given the tremendous growth in computer networks during the period between 1970 and 1980.

DNS servers were the solution that everyone was waiting for thanks to the work done by Paul Mockapetris’ which cast light towards this direction.

Over the years the architecture and use of DNS servers has been extensively researched on and applied in order to enhance web security and fast web browsing. (Find out more about DNS here)

Here are some of the most interesting facts about DNS servers that you probably never knew about.

100 Million Registered Domain Names

According to Domain Tools Statistics, there are over 100 million domains registered in the whole world (and most of us probably visit 10 domains on a daily basis). Most of these domains are associated with businesses, small organizations and individuals. This pretty much shows how effective the use of DNS has been to the currently technological landscape.

30 Years Old

Many people usually think that DNS servers are a new invention that was created in the 21st century. However, DNS servers trace their roots back to November 1983 from two papers that were published by Paul Mockapetris. These papers were named RFC 882 and RFC 883. Since then, more work has been done in order to make DNS servers as effective and secure as they are today.

Started Off With 6 Original Top Level Domains

Top level domains refer to the .org or .com prefix of websites. Currently there are over 700 top level domains (with some having queer prefixes such as .soy). It’s even more interesting to note that the first top level domains to be implemented in the 80s were only 6. This six top level domains included; .com, .org, .biz, .mil, .net and .edu.

The influx in top level domains can be attributed to an ambitious goal set out by ICANN (Internet Corporation for Assigned Names and Numbers) in 2011. They embarked on a campaign of better mapping out domains according to their uses by releasing new top level domains.

Forward And Reverse DNS Lookups

Did you know that DNS not only convert host names to IP addresses, but can also convert IP addresses to domain names as well? The former is known as a forward DNS lookup whereas the latter is referred to as a reverse DNS lookup. While reverse DNS lookups are rarely used (who’s going to remember an IP address instead of a host name?), they usually help network administrators whenever they want to troubleshoot certain domain aspects by using utilities like ping.

Highly Targeted For Hacking Purposes

One major disadvantage of DNS is that it is highly targeted for hacking purposes. Many hackers usually try to gain access to the DNS server records of particular websites. If successful, they can be able to redirect users to their own sites where they can carry out phishing of user information or carry out other malware attacks.

By being able to understand how DNS servers work, you can be able to know how best to protect your devices and sites. Apart from it being highly targeted by hackers, DNS servers certainly have great advantages that can be leveraged for both personal and business usage.

Furthermore, with proper security channels properly configured, you will never have to worry about the security of your information being compromised.

The Working Principles Of DNS Servers

Before you get to understand the working principles of DNS Servers, it’s important that you understand domain names first. Domain names are usually formed from several parts which are normally separated by dots. The basic form of a domain involves at least two parts. Domain names are usually labelled from right to left. The extreme right part is known the top level domain i.e. .com, .org etc. Each subsequent level located on the left of the domain name is known as the sub domains.

Domain Levels

Generally, a domain name can be divided into 127 levels with each part containing not more than 63 characters. For example let’s say that you have a domain xyz.com and you have two locations of your business south and north. Therefore, the domain for the south will be south.xyz.com and for the north will be north.xyz.com. Let’s further assume that you are located in the north and you have your own subdomain therefore it will be chapx.north.xyz.com. These levels can continue being added until you reach the maximum of 127 levels.

However, while adding each level you also have to consider a 254 character limit for your domain name.

DNS Servers And Working Principles

Each domain and subdomain supports multiple DNS Servers. This DNS Servers usually contain all the information about that particular domain. The main working principle of DNS Servers goes like this. A user enters a domain name in the web browser e.g. north.xyz.com. However, in order for them to receive corresponding data for that domain name, it’s necessary that the domain name is converted into a machine readable state known as an IP address. This means that the IP-address of the server will be requested from the data center before you can be able to access your site.

Note: If you are interested in finding out the IP address of each site, then you can use the ping command. To access it, you need to run the command window in Windows. Search for cmd (In Windows 10/8/7) then click on it. In the resulting window, type ping followed by the site name e.g. ping north.xyz.com then press enter. Afterwards a window will appear displaying a group of numbers (e.g. 185.152.25.25), which are the site’s IP address.

Host Names And IP Addresses

It’s important to note that domain names don’t necessarily equal to one IP address. Many domain names can have a specific IP address whereas one name can be related with a number of different IP addresses.

DNS Servers Back up

You might be wondering where all the information on the internet is stored and how it can be retrieved in case websites go down. Well, there are 13 servers around the world which contain the same information. These 13 servers are known as the root servers because they are the ones that hold the entire internet.

Forward And Reverse DNS

DNS Servers not only convert domain names to IP addresses, but they can also convert IP addresses to domain names. The former is known as forward lookup whereas the latter is known as reverse lookup.

1. DNS Records

There are generally six categories in DNS records. These include;

2. A Record (Address Record)

This record is the one that normally links up domain names to a specific IP address.

3. CNAME

Known in full as Canonical Name, it’s a tool which is used to divert requests to an alternative name

4. MX (Mail Exchanger)

This refers to the tool that is responsible for the mail exchanges for that particular domain.

5. PTR (Pointer Record)

This record is used for connecting the domain name to the established CNAME.

6. Ns (Name Servers)

Name server is an alternate name for a DNS Server. It generally points the domain name to the DNS Server.

7. SOA (State Of Authority Record)

The SOA refers to a server which has all the standard information for that particular domain.

Conclusion

You are probably confused by now of what DNS server software to use. The good thing is that many machines come with pre-installed server software that you can make use of unless you feel the need of changing it.

Here is guide on how to configure DNS server software on your Windows machine.