2.6 DNS Record Configuration

DNS A Records

DNS records for IPv4 addresses; will have domain name AND the IP address.

- ex. www.professormesser.com IN A 162.159.246.164 ; Professor Messer

DNS AAAA Records

DNS records for IPv6 addresses; will have domain name AND IP address.

Mail exchange record (MX)

IP address where all emails will be delivered for a certain domain.

Text records (TXT)

Holds human-readable text information for certain purposes like:

- verification to ensure you're an admin making DNS changes

- email security

Sender Policy Framework (SPF)

A list of all email servers that can send emails using the domain name.

- prevents spoofing as if it's from someone else

Domain Keys Identified Mail (DKIM)

Digital signature for outgoing mail; mail servers will validate this. Uses a public key.

Domain-based Message Authentication, Reporting, and Conformance (DMARC)

Validates mail but goes beyond that and allows for configuration on what a mail server will do when validation fails (can accept spam, send to spam folder, or reject email)

Time To Live (TTL)

How long a device will keep a DNS record in its cache; after the TTL ends it's removed from the cache; if the device needs to communicate to the server again, it'll need to rerequest for that specific record.