6.5.6 - Mail Exchange, Service, and Text Records

Flashcards covering Mail Exchange (MX), Service (SRV), and Text (TXT) records for the Network+ exam.

What is a Mail Exchange (MX) record?

Identifies an email server for the domain; multiple servers are installed for redundancy, and each is represented with a record; each server record is given a preference value with the lowest numbered entry preferred.

What are the requirements for the host identified in an MX record?

The host identified in this record must have an associated A or AAAA record and must not point to a CNAME record.

What is a Service (SRV) record?

Contains the service name and port on which a particular application is hosted; often used to locate VoIP or media servers; essential for Microsoft’s Active Directory to locate domain controllers.

What is a priority value in the context of SRV records?

A value used to configure the priority of SRV records.

What is a TXT record?

Used to store any free-form text that may be needed to support other network services; commonly used as part of Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM).

What is an SPF record?

Lists the IP addresses or names of servers that are permitted to send email from a particular domain and is used to combat the sending of spam.

What is a DKIM record?

Used to decide whether you should allow received email from a given source, preventing spam and mail spoofing; can use encrypted signatures to prove that a message really originated from the domain it claims.