DNS Configuration - CompTIA A+ 220-1201 - 2.4

DNS (Domain Name System)

- Translates human-readable names into computer-readable IP addresses

- Hierarchical

- Referred to as a distributed database

RR (Resource Records)

- The database records of domain name services

- Very important and critical configurations

Address Records (A) (AAAA)

- Defines the IP address of a host

- Records for IPv4 and IPv6 addresses

CNAME (Canonical Name Records)

- A name is an alias of another canonical name

- One physical server with multiple services

Mail Exchanger Record (MX)

- Determines the host name for the mail server

- This isn't an IP address; it's a name

Text Records (TXT)

- Human-readable text information

- Can be used for verification purposes

- Commonly used for email security

Domain Keys Identified Mail (DKIM)

- Digitally signs a domain's outgoing mail

- Validated by mail servers, not usually seen by the end user

SPF (Sender Policy Framework)

- A list of all servers authorized to send emails for this domain

- Prevents mail spoofing

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

- Prevents unauthorized email use (spoofing)

- An extension of SPF and DKIM

- You decide what external email servers should do with emails that validate through SPF or DKIM