How to check DNS server operation

DNS is a distributed Internet system that translates machine IP addresses into human-readable website domain names.

How DNS works

The algorithm of actions is quite simple:

1. You type a domain name into your browser. For example, mail.ru.

2. Then the program makes a request to the DNS-server and asks: "How to find mail.ru?"

3. The server responds with "Here is its address - 185.32.189.223".

4. Now your browser knows where to send requests and loads the page.

If DNS does not work correctly, various problems occur:

• Websites won't open even if the Internet is connected.

• Email stops being sent and received.

• The Internet connection may look "broken," although the cause is different.

Thus, the main functions of DNS include:

- tying a site's name to its IP address so that users can refer to sites by clear names.

- verification of mail records, which allows mail servers to exchange letters.

- Ensuring that devices communicate with the Internet.

How to recognize that DNS is the problem

The most common sign of a malfunction is that sites stop loading and give errors like these:

• "Cannot find server";

• "DNS_PROBE_FINISHED_NXDOMAIN" or something similar.

However, it is far from a fact that the problem is DNS - it is quite possible that you just lost the Internet.

To be sure of this, just open the site directly by its IP address. For example, type http://185.32.189.223 (one of the mail.ru IP addresses) into your browser. If the site opens as usual, then the problem is in DNS.

Check DNS settings

First of all, find out what DNS server is used by your device. The settings can be found in the network settings on your computer or in the router control panel.

Public DNS servers are usually faster and more reliable than those configured by default.

Check through the command line using the ping command

Open a command prompt and enter the following command:

ping 1.1.1.1

If the server responds (lines with response times appear), then DNS is available. If there is no response, check your Internet connection.

Online tools to check

If the command line is not to your liking, we recommend specialized online services. For example:

1. DNSChecker - allows you to check the availability of DNS records from different regions.

2. IntoDNS - analyzes the DNS server settings of your domain.

Here everything is very simple: you specify the domain name and select the records you want to check (A, MX, CNAME, etc.). In the end, you will get a detailed report.

Conclusion

Knowing how DNS works helps you quickly identify and fix problems with access to sites, mail, and the Internet. If after all the checks the situation has not improved, you should seek help from specialists.