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What is DNS server | Types of DNS records & DNS over https

We will discuss in detail about what is dns server, types of DNS records present in the server and also how to configure DNS over HTTPS in chrome and firefox.

What is DNS server

DNS stands for Domain name system. The basic role of DNS is to translate Domain name to IP address.

Let’s make it easier to understand.

Computer only understand numbers, it doesn’t understand names. Humans are good at remembering names than numbers. Network engineers built DNS to bridge the gap between humans and computers.

For instance, think there is no DNS you have to remember IP address of all Domain names such as Google, Facebook, YouTube and so on. DNS made our life’s easier by resolving Names to IP address. If DNS is not configured properly you may get the following error ‘DNS probe finished no Internet‘.

How does DNS works

Let’s say you type Google.com in your browser. The request Google.com is sent to the DNS server. Every company will have their own DNS but if you are a normal user using internet at home your ISP (Internet Service Provider) hosts your DNS. DNS check its cache memory to find the IP address of the domain.

If the DNS couldn’t find the term, you searched in its database, this might happen when your searching the Domain name for the first time. At this instance, the DNS forwards the request Google.com to Root level Domain.

Root level Domain

So, what is Root level Domain?

Root level Domain is the highest hierarchical structure of a DNS. DNS send the request to Root domain asking for IP address of the domain. Root domain does not know the IP address, but it know where to find the IP address.

TLD server

Here comes the TLD (Top-level Domain)

TLD are extensions such as .com, .net, .org, and so on, each extension has a separate TLD. Root server identified a domain name based on the extension and sends the IP address of the TLD to the DNS.

The DNS then sends the request to TLD server asking for the IP address. TLD doesn’t know the IP address, but TLD checks its database for the domain name and it know where you can find the address.

Authoritative Name Server

This is the final level.

Authoritative name server has every details of a domain including IP address. When the DNS request IP address, the authoritative server response DNS with the IP address of the domain.

And finally, your computer displays the webpage you requested. This whole step happens in just milliseconds.

What is DNS server | Types of DNS records & DNS over https
DNS caching

DNS caching, when the above process for a domain is done, the DNS stores the information about the domain in its cache memory. This helps to save time, each time you search the domain it does not to repeat the same process, it delivers information that is stored in cache memory of the DNS.

What is DNS server | Types of DNS records & DNS over https

Types of DNS records

You might have this question “What are DNS records”?

DNS records are the most important information stored in DNS server about a domain.

  • A record: A record is an address mapping record that maps every domain name to its corresponding IP address. For example, google.com point to 172.217.6.238 IP address.
  • AAAA record: AAAA record is an IPV6 address mapping record whereas A record has IPV4 address.
  • CNAME record: CNAME record is a Canonical name record often known as alias record. You can keep different alias pointing to same IP address. For instance, If you set CNAME of www,google.com and google.com to same IP address. When a user search any of this term, it takes to the configured IP.
  • MX record: MX record is a mail exchange record. This point to SMTP record which routes all outgoing email.
  • NS record: NS record is a Name server. Every DNS points to a specific zone. For example, .com domain has specific authoritative name server. NS record contains IP address of the authoritative name server.
  • PTR record: PTR record is reverse DNS lookup. This allows the server to return host name for IP address.
  • SOA record: SOA is a start of authority record which contains administrative information such as a serial number, contact details and so on.

DNS over https

Cloudfare is the first to introduce DNS over HTTPS. Before knowing about DNS over HTTPS, let’s have a look at what is HTTPS.

What is HTTPS?

HTTPS is Secure hypertext transfer protocol. This fetches the webpage of a website from the server and also used for encrypting the data.

It encrypts the data that is transferred between the web client and the web server. It runs on the port 443.
What is DNS over HTTPS?

As we saw above DNS is used to translate name to IP. This communication between the DNS will happen in clear text.

This can be prone to different attack such as eavesdropping and man in the middle attack. A person inside your network can easily see your searches. Even the government and your ISP’s can see what website you visit.

Here comes DNS over HTTPS which protects are privacy from intruders.

This encrypts the DNS request that is sent and makes it difficult for your ISP’s to see and block your traffic. DNS runs on port 53, but DNS over HTTPS make the request run in the port 443 making it secure.

How to configure DNS over HTTPS in your chrome browser

For configuring the chrome to run DNS over HTTPS, follow the steps below

  • Type chrome://flags in your chrome browser
  • Enter DNS in the search box
  • You can see secure DNS lookups, make it enabled.
  • Relaunch the chrome browser.
What is DNS server | Types of DNS records & DNS over https

Now, go to the browser and type 1.1.1.1/help and check whether ‘Using DNS over HTTPS (DoH)’ is Yes. Now, your chrome uses DNS over HTTPS.

How to configure DNS over HTTPS in your Firefox browser

For configuring the Firefox to run DNS over HTTPS, follow the steps below

  • Go to options from your firefox settings
  • Type DNS in your search box
  • Click on settings.
  • Scroll down, at the bottom you can see enable DNS over HTTPS option
  • Check the box and click Ok.
What is DNS server | Types of DNS records & DNS over https

Now, go to the browser and type 1.1.1.1/help and check whether ‘Using DNS over HTTPS (DoH)’ is Yes. Now, your chrome uses DNS over HTTPS.

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