What is DNS and DNS-records?
DNS (Domain Name System) is a distributed computer system for obtaining information about domains. Used to get an IP address from a host (website) name. Also, with DNS information, it is possible to find out the hosting provider that serves the domain. For example, our hosting uses NS: dns1.hyperhost.ua, dns2.hyperhost.ua, and virtual servers - vps1.hyperhost.ua, vps2.hyperhost.ua.
Why do we need DNS servers?
What is a DNS server? It is a domain name system tool. With DNS servers, domain names on the Internet work. DNS servers are a service that stores and maintains domain records. If DNS did not exist, then users would have to memorize numbers, not domains, to access sites.
DNS server is a special technology that stores important information for the Internet system. This is not a virtual system, it is physically stored on special devices in a record format. The work of the DNS is also provided by software.
Root DNS servers store information about the root DNS zone. Root servers are managed by different operators around the world.
How to use DNS for your domain?
If you are the owner of a domain, then you must know what the DNS server address is. The domain owner manually points the DNS for the site name in the domain name settings. You can find out these records from the hosting provider where the site is hosted. If the site does not yet exist, then you can use the NS server of your registrar.
The time for updating DNS information depends on the domain zone, as well as on the region from which you are checking. In some cases, the update may take up to 72 hours. To find out the DNS of a specific domain, you need to use the WHOIS service. In the NS server check box, you will see the required information.
How DNS servers work?
In a web browser, the user enters the name of the site, then redirects and searches for matches between the IP address and the domain name. If there is a match, the browser makes an appropriate request and provides information to the user in response. If there are no matches, the request will be redirected to the root server. Then again there is a redirection from the root server to the first level server, then there is a request to the second level server. Requests are sent until a response is found.
A reverse DNS lookup occurs the other way around, when a user tries to find out a domain using an IP address.
What is a DNS zone?
A DNS zone is a part of the DNS under the control of a group of DNS servers, at least two - primary and secondary. The primary stores the original files, the secondary receives data from the primary and periodically requests a database update. The primary server caches the information. Domain records are created in the DNS zones of specific domains.
DNS records types:
What is DNS and DNS records? There are several types of records:
- A record, or address record, links a hostname with an IP address. For example, A-record for the name referrals.icann.org will return its IP address - 126.96.36.199
- AAAA (IPv6 address record) links a hostname with an IPv6 address. For example, AAAA record for the name K.ROOT-SERVRS.NET will return its IPv6 address - 2001:7fd::1
- CNAME (canonical name record) is used to redirect to another name.
- MX record specifies a mail exchange server for a particular domain.
- NS (name server) record points to a DNS server for a specific domain.
- TXT record is a special record that is displayed in text format and can contain any notes.
- SPF record - contains information about servers that can send emails from a domain name. Used to improve security.
- PTR record or reverse DNS record is used to bind an IP and a canonical name to filter mail.
- SOA record contains information about the server where the domain is stored. This is a reference record that is necessary for the DNS system.
The DNS system is created to search for information on the Web. Due to the DNS, websites have symbolic domain names and work fast.