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Head First DNS

  • A records - An A record maps a domain name to the IP address (Version 4) of the computer hosting the domain. An A record uses a domain name to find the IP address of a computer connected to the internet.

  • AAAA records - DNS AAAA records match a domain name to an IPv6 address. DNS AAAA records are exactly like DNS A records, except that they store a domain’s IPv6 address instead of its IPv4 address.

  • CNAME - The ‘canonical name’ (CNAME) record is used in lieu of an A record, when a domain or subdomain is an alias of another domain. All CNAME records must point to a domain, never to an IP address.

  • MX - A DNS ‘mail exchange’ (MX) record directs email to a mail server. The MX record indicates how email messages should be routed in accordance with the Simple Mail Transfer Protocol (SMTP, the standard protocol for all email). Like CNAME records, an MX record must always point to another domain.

  • TXT - The DNS ‘text’ (TXT) record lets a domain administrator enter text into the Domain Name System (DNS).

  • NS - The DNS ‘name server’ (NS) record is used to point a domain or subdomain to a DNS server. The NS record is used to delegate a DNS zone to use a specific DNS server.

  • SOA - The DNS ‘start of authority’ (SOA) record is used to identify the authoritative name server for a DNS zone, and to specify administrative contact information for the zone.

  • SRV - The DNS ‘service’ (SRV) record is used to specify the location of services (for example, mail servers) and the protocols they support.

  • PTR - The DNS ‘pointer’ (PTR) record is used to map an IP address to a domain name. PTR records are used in reverse DNS lookups.

  • SPF - The DNS ‘sender policy framework’ (SPF) record is used to prevent email spoofing. SPF records are used to identify which mail servers are authorized to send email for a domain.

  • DKIM - The DNS ‘domain keys identified mail’ (DKIM) record is used to prevent email spoofing. DKIM records are used to verify that an email message was sent by a legitimate sender.

  • DMARC - The DNS ‘domain-based message authentication, reporting and conformance’ (DMARC) record is used to prevent email spoofing. DMARC records are used to verify that an email message was sent by a legitimate sender.

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Reference: https://www.cloudflare.com/learning/dns/dns-records

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