What is the DNS record? Print

DNS record represents the instructions that DNS server uses to resolve the domain name to proper IP address.

Each DNS record has a parameters:

• Name - Domain Name (host name).

• TTL - Time to live. The value shows how long the record will exist in system cache before the system will query DNS server to refresh the record.

• Type - the type of record. It will be described later. And others.

Basic types of DNS records:

• A-Record (Address Record) - Shows the accordance of the domain name to it's IPv4 address.

  | Name               | TTL           | Type  |  IP      |
  |--------------------|---------------|-------|----------|
  | www.domain.tld     | 10800         | A     |1.2.3.4   |
  

  DNS server returns the IP address 1.2.3.4 of domain name that was requested (www.domain.tld). A-Record is the only record that could be made the root host record.

• AAAA-Record - The same as A-Record except that AAAA-Record uses IPv6 address.

• CNAME-Record (Canonical name record) - Used to map alias to it canonical name.

  | Name               | TTL   | Type  |  Data             |
  |--------------------|-------|-------|-------------------|
  | domain.tld         | 10800 | A     |www.domain.tld     |
  | example.org        | 10800 | A     |www.domain.tld     |
  

  CNAME record are being handled the same as A-records. DNS server maps you on www.domain.tld when you request example.org. It could be useful in case the IP address of domain changes often enough. Then you do not need to change IP address of each alias, just modify A-Record that points to domain.

• NS-Record (Name Server Record) - Shows the DNS server responsible for the zone.

  | Name               | TTL   | Type  |  Data             |
  |--------------------|-------|-------|-------------------|
  | ns.domain.tld      | 10800 | A     |10.11.12.13        |
  | example.org        | 10800 | NS    |NS.domain.tld    |
  

  NS.domain.tld - is the host which name servers will query for records in the example.org domain. Please note that this value could not represent CNAME record. This value should primarily be a record but could use an IP.

• MX-Record (Mail Exchange Record) - Show mail servers where the mail should be delivered to.

  | Name          | TTL   | Type |MX Level |  Data              |
  |-------------  |-------|------|---------|--------------------|
  | www.domain.tld| 10800 | MX   |10       |mail.domain.tld     |
  | www.domain.tld| 10800 | MX   |20       |res.domain.tld      |
  

  The name field of an MX record contains the host name which appears in the e-mail address, and the data field contains the hostname of the server to which the mail should be delivered. MX LEVEL here is the priority of record. The lower the number the higher the preference. mail.domain.tld will be tried first. Data - the host names which will have mail delivered to them for the domain. Data can not be CNAME value as well.

• SPF-Record (Sender Policy Framework) - Defines which servers can send mail from present domain.

• SRV-Record (Service Record) - Defines the servers for specified services.

• SOA-Record (Start of Authority) - Defines the DNS server providing authoritative information about a domain name, the email of the domain administrator, the domain serial number, and several timers relating to refreshing the zone.