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What is a DNS server, how to find out your preferred provider address, replace it with Google Public DNS or alternative options. Checking domain DNS records - what is it and why is it needed? Internet dns service provides

What is DNS, how it works and how to specify or change DNS servers for a domain - 3.5 out of 5 based on 2 votes

DNS - (Domain Names System) Domain Name System - is a network service on whose servers domain names are compared with the digital values of their IP addresses.

Let's take a closer look at what DNS is, how it works and how it works.

The Internet is an IP network and each computer on this network has a specific personal number, which is called an IP address. But since it is not convenient to use digital addressing, it was decided to use alphabetic writing of addresses. Therefore, when accessing any sites on the Internet, you enter letters, not numbers. But the problem is that computers can only perceive digital information, that is, a sequence of ones and zeros, and are absolutely unable to understand letter information.

That is why a special service was created on the Internet that converts the alphabetic spelling of addresses into numbers and this service is called DNS (Domain Name System).

The DNS service is a huge database that contains information about the correspondence of a specific domain name to a specific IP address. Visually it can be depicted like this:

There are a huge number of domain names on the Internet and there are more and more of them every day, so you can imagine how huge the database of this service is. Storing such a large amount of information on one server is unreasonable and practically impossible.

But since the Internet consists of subnets, it was decided to split this database and place a certain size of it in each of the subnets. Where IP addresses correspond to domain names only for computers included in a given subnet.

What is NS server

The server that contains all the information about the correspondence of domain names in a specific subnet is called the NS server, which stands for Name Server or name server. Let's look at an example of converting a domain name to an IP address based on a simplified network.

As you can see, on this network there is a computer with an alfa domain with an IP address of 192.55.11.25 and a computer with a beta domain with an IP address of 192.55.11.26, as well as a DNS server itself, which also has a corresponding IP address. Now let’s assume a situation that computer beta needs to contact computer alfa, but it does not know its IP address, only its domain name. However, he knows the IP address of the DNS server which he contacts to find out the IP address of the alfa server. The NS server searches its database and, having found the IP address that matches the alfa domain name, transfers it to the beta computer. The beta computer, having received an IP address, uses it to contact the beta computer.

As you know, all domain names have their own hierarchical structure and are divided into domain zones.ru. com and others. See the material for more details. So, each domain zone has its own NS server containing information about the IP addresses of those domains that are included in a certain domain zone. Thus, this huge database is divided into smaller ones.

DNS Settings

How can you change and specify the DNS server for a domain.

In order for it to load when you enter the address of your website into the address bar of your browser, you need to link the site’s domain name with hosting. To do this, we must inform the DNS service which NS server needs to be contacted, so that it, in turn, looks in its database and tells which server (hosting) the browser should contact.

The DNS server record looks like this:

ns1.yourhosting.ru
ns2.yourhosting.ru

You can find these addresses:

in the letter sent to you by the hosting provider immediately after ordering hosting;
in the hosting control panel, for example in the domains section;
by contacting hosting support.

Now about where they need to be indicated. These DNS server addresses must be specified to the domain that you are going to use as the address of your website. Therefore, go to the website of the domain name registrar where you registered your domain. In domain management, find the DNS server item or DNS Server Management / Delegation, the name may differ depending on the registrar. For example, at the domain name registrar that I use to register my domains, you need to go to the “My Domains” section >> select the desired domain and select “Change DNS servers” from the drop-down list.

After entering this section, a form will open in which you need to enter the appropriate DNS servers. To do this, in my case, you need to uncheck the “Use registrar names” option and then specify ns1.vashhosting.ru in the DNS1 field, and ns2.vashhosting.ru in the DNS2 field. IP addresses may not be specified, so some hosting providers do not issue them. After filling in the fields, click the "Edit" button.

After this, you need to wait some time until the DNS servers are matched. This may take from several hours to a whole day. Therefore, as soon as you specify them, your site will not load.

How to specify your DNS servers for a domain

Sometimes you need to specify your DNS servers, i.e. DNS servers that are located in the same domain. Almost all of them have their own DNS server service. In this case, for example, for this site, ns1..site is specified as the DNS server.

The following points must be taken into account:

1. If you specify your DNS servers for a domain located in the RU, SU, RF zones, then you must specify its IP address for each DNS server. In this case, each specified IP address must differ by at least one digit; it is not permissible to indicate the same IP.

2. If the DNS servers that you specify for your domain name are in another domain, for example, if for a website domain you specify DNS servers like 1ns.vash-sait.ru or 2ns.vash-sait.ru, then you do not need to specify IP addresses .

3. If you specify your DNS servers for an international domain, then these DNS servers must be registered in advance in the international NSI Registry database. It is not possible to indicate them without registering in this database. When registering with NSI Registry, you will be required to enter IP addresses for each DNS server. Therefore, when specifying DNS servers for a domain, there is no need to specify IP addresses.

Attaching an IP address to a domain

To attach an IP address to a domain, you need to go to the DNS records settings. How to do this will depend on your hosting control panel. For example, in ISPmanager you need to go to the “Domain Names” section, then double-click on the required domain name and specify or edit the following three entries (to create an entry, click on the “Create” icon; to edit, click on the required entry):

For the first entry, enter www in the “Name” field, select A (Internet v4 address) in the “Type” drop-down list, and enter the required IP address in the “Address” field.

For the second entry, enter @ (dog) in the “Name” field, select A (Internet v4 address) in the “Type” drop-down list, and enter the required IP address in the “Address” field.

For the third entry, enter * (asterisk) in the “Name” field, select A (Internet v4 address) in the “Type” drop-down list, and enter the required IP address in the “Address” field.

Video: How the DNS system works

Material prepared by the project:

Hello, dear readers of the blog site. We have already talked about this and that. They talked about this and that. However, there is also the technical side of the Internet, which is also very important and interesting in its own way.

So, here you go DNS is one of the fundamental things on which the entire Internet is built. This abbreviation stands for Domain Name System, which means domain name system.

I already touched on this issue (the structure of the domain name system) when I talked about it, but only in passing. Today I want to talk about the role of DNS servers in the operation of websites and the entire Internet as a whole.

Why do we need DNS servers and what are they?

The domain name system operates with full names (Latin letters, numbers, dashes and underscores are allowed when forming them)..120.169.66 is not very informative) and it is easier to operate with them.

The latter relates specifically to the human factor, because it is still more convenient for machines to use IP addresses, which is what they do... But he understands that this is a domain name, which means information about what IP the site is located on, he will be able to receive from the DNS server.

It is on these DNS servers (sometimes they are also called N.S. from the Name Server, i.e. server names) and the entire Internet is supported (like a flat world on three whales standing on a turtle). which does not require direct human participation in its work (if you set it up, it works 24/7). And there are a lot of such DNS servers on the network.

How does DNS work and what does the Hosts file have to do with it?

At the dawn of the Internet, DNS didn't exist at all. But how did the network work then? .120.169.66? The so-called was responsible for this matter then (and now too), where all the hosts of the then small Internet were registered.

Such a file was (and is now) on every user’s computer (yours has it too) connected to the network (see the link above for how to find it).

In the Hosts file several thousand lines were written (according to the number of sites on the Internet at that time), in each of which the IP address was first written, and then the corresponding domain, separated by a space. This is what an entry for my blog would have looked like if it had existed on the Internet twenty-five to thirty years ago:

109.120.169.66 website

Good luck to you! See you soon on the pages of the blog site

Types of Domain DNS Records

Converting domain names to IP is one of the few features. Besides DNS does others too. DNS record types are used to implement them. Let's list the most common ones:

Records that determine the IP address of a device by domain name are assigned type A(or AAAA for IPv6).
You can set any number of domain names for the same IP address. In this case it is used CNAME record type, which defines an alias for the domain name.
MX record type helps you find out the address of the mail server where you want to send mail. There can be multiple MX records for one domain.
TXT- a record that includes text data. Used to transmit information, for example to verify the owner of a domain, or to confirm the security of an email. There can be any number of text entries. Added in domain settings.

There are many other types of records, but they are used much less frequently.

What records affect the delivery of letters?

There are special TXT records, the presence of which determines whether letters will end up in the inbox or will be blocked before they appear in mailboxes.

Who do you think reads your letters before they are delivered to the recipient? CIA, Mossad or MI6? No, they will be read by spam filters, which are constantly being improved and increase the number of factors for determining spam. Getting into the spam resource database (blacklists) will seriously complicate your life if you regularly send out mailings.

Authentication DKIM, SPF, DMARC will confirm the authenticity of the domain and ensure delivery of letters to the mailbox. They actively guard the reputation of the domain and protect against phishing and spam.

DKIM- digital signature of the sender, which confirms that the letter was sent from your domain. The receiving email service automatically checks this signature and makes sure that the letter was sent by you and not by scammers.

SPF- a domain record that contains information about the list of sending servers and letter processing mechanisms. This entry poisons the life of spammers and scammers in passing antispam systems. Clearly indicates who has the right to send letters on behalf of the domain and who does not.

If the domain is not protected SPF entry And DKIM signature, nothing will stop spammers from sending letters on your behalf. Mail services check incoming correspondence for the presence of SPF and DKIM records and their absence is regarded as spam.

But these mechanisms also have disadvantages. To make it easier for the mail service to distinguish real emails from fake ones, in addition to SPF and DKIM, they introduced another level of protection - DMARC. When these 3 factors work simultaneously, the probability of successful delivery of messages to the recipient increases many times.

DMARC determines what to do with messages that have not passed SPF and DKIM authentication. If DMARC is configured correctly, fraudulent emails will be rejected at the analysis stage, and the email will never reach your mailbox. You yourself prescribe the algorithm of actions for what the mail server should do if any SPF and DKIM conditions are violated.

Tools for checking domain records

We figured out the recording settings. Now our letters simply must end up exclusively in the inbox, and spam analyzers of mail services take off their hats when they encounter our mailing list. Is this really so and where can I be sure that everything was done correctly?

For checking DNS records and domain diagnostics, special services have been created:

MXtoolbox - checking DNS records, full domain diagnostics and additional tools for site analysis.
DNSstuff.hostpro.ua- here you will receive complete information about the DNS settings for your domain and find out whether it is in the blacklists.
Functions-online.com- checks DNS records.
2ip.ru- checking DNS domain records and full site analysis.
Mail-tester.com- tests letters to see if they end up in spam, points out errors in links, checks domain records and the quality of letter formatting. Simply send an email to the address provided, then check the rating.
Pr-cy.ru- checking DNS records and site status.

They will be useful if problems are noticed. For example, mail stopped arriving or sending etc. A similar failure usually occurs after corrections to DNS records. Therefore, after changes are made, it is necessary to carry out checks.

Checks are also necessary to diagnose the general health of the domain, so that users do not have difficulties finding a resource on the network. The slightest error in DNS records will close access to the site and efforts to promote it will fail.

Example of checking DNS records using MXtoolbox

We think this is one of the best domain diagnostic services. It is most often used technical department specialists to identify problems with clients and provide assistance to them.

Mxtoolbox allows you to conduct general diagnostics of a domain, detect its presence in blacklists, check the correctness of MX records and other DNS records, and even test the likelihood of your emails being delivered to Inbox. Timely testing will allow you to avoid problems with mail providers.

At this moment, the domain is checked for placement in blacklists while other problems are identified. As a result, we get a domain health report:

The domain is healthy if there are no problems identified in red. But the result of the test showed the presence of errors that need to be eliminated - the absence of SPF and DMARC records.
We take the records automatically generated by the Estismail service and make settings on the hosting. Next, we check the correctness of the changes made.

Go to the website mxtoolbox.com.
Click on the orange arrow button. From the drop-down list we are interested in SPF Record Lookup, DKIM Lookup and DMARC Lookup.

How can I check if my DKIM record is correct?

Enter the domain in the verification field in the following format - example.com:estismmail. Enter without http:// And www. Instead of example.com enter your domain, and after the colon indicate the selector. Choose DKIM Lookup.

In the window that opens, you will see a “successful” message like this:

If after the check a picture opens with a message that DKIM was not found, you will have to update the DNS records.

How to check SPF record?

SPF record verification occurs in the same way as DKIM verification. From the list that opens, select SPF Record lookup. In the appropriate field, enter the domain name without http:// And www. If the settings are correct, you will see this picture:

In the bottom column in the line SPF Syntax Check will be displayed The record is valid .

The most common situation, besides having no SPF entry, is having 2 or more SPF entries. If such an error is made, you will see the following in the window that opens:

In this case, correct the SPF entry - simply combine all nodes in one record, from which you send mailings, as indicated in the “correct” previous figure.

How to check DMARC record?

When checking DMARC records, the principle is the same as in the first 2 cases. Select a function from the list under the orange button DMARC Lookup and enter the domain name without http:// and www.
If the correct entries are entered, you will see the following table and a message at the bottom in the DMARC Syntax Check line stating that The record is valid.

Yes, it’s difficult for emails to get into the inbox. But by fulfilling the conditions listed above, you will significantly facilitate the path of your messages to the heart of the recipient. Keep your finger on the pulse of your domain, its healthy condition is no less important than your personal well-being.

Everyone who deals with website development is familiar with the conceptDNS addresses . In this article we will look atfeatures of working with DNS and all the important points that should be taken into account when setting it up correctly.

DNS – stands forDomain Name Server/System, that is, it is a distributed system for obtaining information about domain zones. It is most often used to obtain an IP address by host name, because each site existing on the Internet is assigned a specific IP address.

DNS servers is a set of servers located on the Internet that transmit data between themselves in real time about domains. Essentially, it is a system for managing the world's domain names. There are several types of DNS servers, depending on the functions they perform:authoritative , caching , local, redirect, root, registry and DNSBL server .

Eg, authoritativeresponsible for a specific zone;cachingserves customer requests;localused to serve DNS clients that run on the local machine; In most casesredirecting the server is used to reduce the load on the caching DNS server;root– authoritative for the root zone, there are only 13 root servers in the world;recordingaccepts updates from users;DNSBLuses the same mechanism and protocol as DNS servers.

If you have incorrectly configured the DNS of your site, this can negatively affect its performance, and for a long time. DNS changes are not carried out immediately, so when entering information you should be quite careful and avoid mistakes.

What is included in the main parameters of a domain NS record:

Type A record – converts from language format to digital. It is also necessary for connecting the domain and hosting where the site is located;
AAAA Record(address record for IPv6) – associates a host with an IPv6 address. The AAAA record is the exact equivalent of the type A record described above, but has a different appearance.
CNAME record(canonical name record) or canonical name record redirects to another name. A CNAME is a canonical name or a synonym of an existing hostname, which must have an A record.
TXT record – additional records that are used mainly for setting up mail;
MX – this is a record that identifies the mail server for the domain and helps configure the exchange of mail messages from the domain;
IP – shows the unique server address where your domain or hosting is located;
NS records – are intended for connecting your domain and hosting, as well as for domain delegation.

Why indicate the name server (DNS) of the hosting you are currently using in your domain record?

Using a name server, you can find information about your site. If you leave an old entry about your previous hosting, the direction will go to a server on which your resource no longer exists. And if the provider has deleted records about your site, then the domain pointer will lead to nowhere.

How long does it take for changes to change hosting providers to take effect?

In general, the dissemination time for information is 24-72 hours. This happens because DNS servers only update information periodically. This is only the average waiting time, it can be 5 hours, but it can be over 72, so you should be patient.

Set up your website's DNS You can do this yourself using the domain control panel in the appropriate DNS section, or you can ask the technical support of your hosting provider to do this.

DNS settings depending on the selected service - or . The basic steps in setting up DNS depend on which hosting provider you use. For example, if you have regular virtual hosting, then this greatly simplifies the situation, since all settings are created automatically. You only need to delegate the domain to the hoster's NS server. This method is an ideal solution for beginners in this area, but such users have minimal rights in setting up DNS. If you need to control a domain zone and you have chosen a virtual dedicated server service for your website, then you should use the registrar’s servers or public services. You can, of course, create your own name servers, but this is best done if you plan to open hosting. Public services, for example, include Yandex servers.

If you ordered one of the servicesin company Hyper Host™ , Yours should be sent to our servers. This can be done in two ways:

1) Submit the A-record of the domain in the control panel of your domain (control panel at the domain name registrar);

2) Change the NS servers to those that we provide:

dns1.site

dns2.site

Haven't registered your domain yet? Then we have about domain registration. We also bring to your attention ““.

If you need help with this or other issues, please contact 24/7 technical support. We will always be happy to help you!

What is an rDNS record for? Read more in the article on our blog.

A site’s DNS (Domain Names System) is a system for distributed storage of keys and their values that link information about the actual site’s domain name.

How DNS works

In this way, the Internet solved the problem of connecting domain names with the real Internet routing system - IPv4 and IPv6 addresses. The creators simply added a site directory function and called it DNS.

Interesting fact

When the Internet spread over only a few computers, and the number of sites could be counted manually, the well-known hosts file was used to connect the domain and IP of the computer. The addresses of web pages were manually written in it in pairs with the addresses of servers serving this domain. Instead of 128.0.0.2, you could enter mysit in the / address bar of the browser e .com and get to the desired resource. But when the network grew to immense size, the need arose to create a centralized and constantly updated array. Hosts has been replaced by a common DNS.

Let's consider the entire chain of requesting information about the site:

You entered the site name in the address bar of your browser, for example yandex.ru.
The browser recognized that it was clearly not an IP address, which means it needed to be obtained manually. The browser generates a request to the most convenient DNS server.
The DNS server, having received a request from the browser, requests information about the site along a long chain that reaches the root servers.
After receiving the response, DNS sends as a response the IP address of the server to which the specified domain name belongs.
The browser directs you directly to the IP.

We talked about contacting root servers, which was a valid but rather rough rounding of DNS routing information

Root servers

Root servers are the 13 main DNS servers that serve all existing websites in the world. All root servers are located in the USA.

There are 9 replicas of these storage facilities in Russia, in the following cities: Moscow, St. Petersburg, Novosibirsk, Yekaterinburg and Rostov-on-Don

In real conditions, one request out of a thousand reaches the root node. If each browser request led to the passage of the entire chain of world servers, we would wait tens of times longer for loading, and at peak times we would not receive a response at all due to overloads. It turns out that the developers have created a powerful distributed data caching system.

If you once requested a domain, its data is stored in the server cache for a very long time. When you contact again, DNS will not check the IP with other servers in the chain, but will simply give you the answer it received earlier.

How to find out the DNS of a site

In order to find out the DNS of a site, there are simple and free tools. They all simply follow the browser's steps, displaying the servers' response headers.

Go to the service page: https://2ip.ru/dig/.
Enter the domain name of the resource you are interested in in the “Domain” field.
Select the type "ANY" and click "Check".
All available information about the domain will be displayed on the screen.

How to set up and register a site's DNS

Let's consider step by step the process of setting up parameters for a web resource.

After completing the domain registration process, you will be prompted to go to your control panel for delegation. Go to the NS records management section.
For many, it is much easier to keep the site server and DNS records under one account, so domains are delegated to the hosting company’s DNS servers. To perform this procedure, check with your hosting provider for the NS server addresses and enter them in the domain settings.
If you want to leave the default NS records, further configuration will have to be done in the control panel of the registrar. If you have changed the NS to the hosting server, go to its control panel and add your domain to the list. Most often, the procedure receives a technical response within 48 hours; do not expect the domain to appear on the list instantly.

After completing all the initial configuration settings, you can proceed to directly configuring the parameters of DNS records. Each control panel has its own characteristics, but the principle is the same - select the domain editing mode, change/add/remove the required parameter-value pairs, save, and after 24-72 hours the result is reflected on the site

Basic DNS resource records

ATTENTION: There is always a dot after the hostname in DNS

A yourdomain.com. A 127.0.0.1

The main setting of any domain. Association of a name with an IP address. Configured by you immediately after delegation.

CNAME sub.yourdomain.com. CNAME yourdomain.com

Subdomain creation tool. If you create a subdomain on the site, specify it in the CNAME directive, otherwise it will not be accessible.

MX mail.yandex.ru. MX 0

Record a mail server for your site. Without specifying this directive, sending and receiving mail for the site will not be possible. If you use third-party services, such as Yandex.Mail, carefully read the instructions for using this directive. The value of the second parameter is set to a priority number from 0 to 65535, where the priority decreases as the number increases. This means that attempts to contact servers will begin with the highest priority, but if it fails, they will go further down the hierarchy.