CompTIA Network+ (N10-008) — Question 527

A network engineer performed a migration to a new mail server. The engineer changed the MX record, verified the change was accurate, and confirmed the new mail server was reachable via the IP address in the A record. However, users are not receiving email. Which of the following should the engineer have done to prevent the issue from occurring?

Answer options

• A. Change the email client configuration to match the MX record.
• B. Reduce the TTL record prior to the MX record change.
• C. Perform a DNS zone transfer prior to the MX record change.
• D. Update the NS record to reflect the IP address change.

Correct answer: B

Explanation

The correct answer is B because reducing the TTL (Time To Live) before making DNS changes allows for quicker propagation of the new MX record, minimizing downtime. Options A and D are incorrect as they do not address DNS propagation issues, while option C is not relevant since a DNS zone transfer is not necessary for a simple MX record update.