DNS servers: the heart of the internet

Domain Name Servers (DNS), are the heart of the internet. They work just like a phone book. You type an address in the address bar, search the DNS servers to which that address belongs, and load the page.

Just as on your mobile phone you have a phone number associated with a contact, there are DNS servers to know who a web page belongs to. You tap on the contact’s name but that name has a phone number associated with it. Likewise, web pages have an associated IP address, computer or server on which they are hosted.

IP address and DNS servers

When you put an internet website in a browser, it will be accessible through the numeric IP address of the web server hosting it. This page currently has the IP address of 82.98.132.21 but may change in the future. Refers to the address of the server where it is hosted.

However, IP addresses are not easy to remember for humans, just as it is not easy to remember a phone number. Using the IP address to identify online resources is also not practical as Internet services occasionally have to move to a new IP address (if they change service providers, for example).

Because the use of IP addresses for websites is neither practical nor easy to use, the domains were created. For example, this page has the domain or avertigoland.com. The global domain name system works a bit like a phone book for the Internet. If you know the domain name of the website you want to visit, the domain name system is used – invisibly and automatically – to find the corresponding IP address of the web server where the website can be found.

IP-to-domain relationship

Then, when you type https://avertigoland.com, your computer identifies the page with its ip, 82.98.132.21, and sends a request to the website to display the information on this page in your browser. The system for searching for a domain name works on the basis of a hierarchy. When you write https://avertigland.com, your computer first connect to a server to request access to that address. If the IP associated with that domain exists, the page is displayed.

How DNS servers work

The default DNS server is usually managed by your Internet provider, but it is possible to use a different one. If someone has recently accessed this web page, the DNS server will “remember” the details and display the correct IP address. Otherwise, it will refer the consultation to a higher level of authority, where the process continues. At the highest level of authority are the “root servers” that ultimately collect DNS servers.

These root servers are very robust and have huge capabilities. They have so much capacity that they will continue to work efficiently even when major attacks occur (so-called denial-of-service attacks).

How to change DNS

The DNS server is a choice of the computer you use. You can either do nothing and navigate with the DNS of your IPS (internet service provider) or change them manually. I’m going to explain how to change DNS servers on Windows and Mac.

DNS change in Windows

Here are the steps to change DNS in Windows 10 (Microsoft Help).

1. Select the Start button,  and then choose Network    >  Internet Settings.  
2. Do one of the following:
   • For a Wi-Fi network, select Wi-Fi  >  Manage Known Networks. Choose the network you want to change settings to, and then select  Properties.
   • For an Ethernet network, select Ethernet,  and then choose the Ethernet network you’re connected to.
3. Under IP Mapping,select  Edit.
4. Under Edit IP Settings,select  Automatic (DHCP)  or  Manual.

4. Manually specify IPv4 settings
   1. Under Edit IP Settings,choose  Manual,  and then turn on  IPv4.
   2. To specify an IP address, in the IP address, Subnet prefix lengthboxes,  and Gatewayboxes, type the IP address settings.
   3. To specify a DNS server address, in the Preferred DNS and  Alternate  DNS boxes,type the addresses of the primary and secondary DNS servers.
5. Manually specify IPv6 settings
   1. Under Edit IP Settings,choose  Manual,  and then turn on  IPv6.
   2. To specify an IP address, in the IP address, Subnet prefix lengthboxes,  and Gatewayboxes, type the IP address settings.
   3. To specify a DNS server address, in the Preferred DNS and  Alternate  DNS boxes,type the addresses of the primary and secondary DNS servers.

4. When you select Automatic (DHCP),the IP address and DNS server address settings are automatically set by the router or other access point (recommended).
5. By selecting Manual, you can manually set the IP address and DNS server address settings.
6. When you’re done, select Save.

DNS change in MAC

The steps to change DNS on MAC are as follows:

1. Select the MANZANA  button in the upper-left corner, and then choose System Preferences.
2. We choose the RED option.

3. Now tap Advanced.

4. Finally, we go to the TCP/IP tab and  from there we can add the new DNS servers.