DNS (Domain Name System) is a hierarchical and distributed naming system for computers, services, or other resources connected to the Internet or a private network. Various types of DNS records exist to serve different purposes. Here’s an explanation of some common DNS record types:
- A (Address) Record:
- Maps a domain or subdomain to an IPv4 address.
Example:
example.com. IN A 192.168.1.1 - AAAA (IPv6 Address) Record:
- Similar to the A record but maps a domain or subdomain to an IPv6 address.
Example:
example.com. IN AAAA 2001:0db8:85a3:0000:0000:8a2e:0370:7334 - CNAME (Canonical Name) Record:
- Creates an alias of one domain to another, allowing the same IP address to be used for multiple domain names.
Example:
www IN CNAME example.com. - MX (Mail Exchange) Record:
- Specifies the mail servers responsible for receiving emails on behalf of the domain.
Example:
example.com. IN MX 10 mailserver.example.com. - TXT (Text) Record:
- Contains text information and is often used for verification and authentication purposes.
Example:
example.com. IN TXT "v=spf1 mx -all" - PTR (Pointer) Record:
- Used for reverse DNS lookups, mapping an IP address to a domain name.
Example:
1.1.168.192.in-addr.arpa. IN PTR example.com. - NS (Name Server) Record:
- Specifies authoritative DNS servers for the domain.
Example:
example.com. IN NS ns1.example.com. - SOA (Start of Authority) Record:
- Contains administrative information about the domain and the zone.
Example:
example.com. IN SOA ns1.example.com. admin.example.com. ( 2023110800 ; Serial 7200 ; Refresh (2 hours) 120 ; Retry (2 minutes) 2419200 ; Expire (4 weeks) 604800 ; Minimum TTL (1 week) ) - SRV (Service) Record:
- Specifies information about available services within the domain.
Example:
_sip._tcp.example.com. IN SRV 10 60 5060 sipserver.example.com.
These are some of the fundamental DNS record types. The specific records you use depend on the services and configurations you need for your domain.