DNS Server : Domain Name Server

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DNS

DNS stands for domain name server. It is just like SSN(Social Security Number). Every specific person has his own specific number. Same thing works for websites as well. Every website has its own ip, but for normal people it is hard to remember ip, so dns converts the name into ip address, so that it is easy for humans to memorize the name of website while machine can use the ip address.

Importance Of DNS

As I mentioned in the introduction, a domain name server is very important. As this server is the one which is responsible for converting the name of a website to its ip address. Lets take a example if you will search for “www.google.com” then you at the bottom you will see a ip address coming. It might be : 216.58.197.78. So for us Google’s address is “www.google.com” but for computers it is “216.58.197.78”. So the conversion that is done when we enter “google.com” is done by DNS server only. So now I hope you would be able to understand the importance of DNS.

Types Of DNS Servers

So if we search or try differentiate DNS, there are two types of DNS that exist.

  1. Primary DNS
  2. Secondary DNS

Primary DNS

This is the main dns that works. It reads data from the zone from a file located on the web server of the hosting account. The data is also shared to secondary dns as well. So this zone data basically tells the server how to behave when a particular server is making the request.

So mostly in the organizational setup we should have 2 dns servers. So tahat if one dns stops then other ones is working and in the meanwhile the first one could be rectified.

One of the main work for the primary dns is also to transfer the data to the secondary dns so that they both have same information. And this procedure is referred as “zone transfer”.

Secondary DNS

Secondary DNS is called as slave server or simply a slave. As for every request it has to contact with the primary DNS server, so that the data between them is same.

It is important to note that a secondary server does not need to pull data form a primary server because another secondary server can be set up as the master server.The secondary DNS is as important as primary because it will play a secondary role, so as the first DNS is down then the secondry DNS would work.

List Of Free DNS Servers

 

1. Google DNS Server

Google Public DNS IPv4 Addresses:

  • 8.8.8.8
  • 8.8.4.4

Google Public DNS IPv6 Addresses:

  • 2001:4860:4860::8888
  • 2001:4860:4860::8844

2. Level3 DNS

Level 3 Public DNS Server Addresses:

  • 209.244.0.3
  • 209.244.0.4
  • 4.2.2.1
  • 4.2.2.2
  • 4.2.2.3
  • 4.2.2.4

3. Open DNS

OpenDNS IP Addresses:

  • 208.67.222.222
  • 208.67.220.220

 

4 .Norton DNS IP Addresses:

Option A:

  • 199.85.126.10
  • 199.85.127.10

Option B:

  • 199.85.126.20
  • 199.85.127.20

Option C:

  • 199.85.126.30
  • 199.85.127.30

5. GRC’s DNS Server

DNS_Server

You can find the related details here : GRC

 

Conclusion On DNS Servers

So this was our short article on DNS Servers. Hope you understood all about the DNS servers. There are many DNS issues that are not addressed in this article. If you are facing any specific issue with DNS you may comment below. Some times you may face dns_probe_finished_bad_config.

You may also face some issues related to DNS Based Malware .

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