CompTIA Updated N10-009 Exam Questions and Answers by sean

To support at least 260 hosts, you need at least 512 total IP addresses (accounting for network/broadcast overhead).

/23 (255.255.254.0) gives 510 usable IPs, ideal for 260 devices with minimal waste.

/24 (255.255.255.0) gives only 254 usable — not enough.

/22 (1022 usable) and /21 (2046 usable) would work but result in significant address waste.

???? Reference:

CompTIA Network+ N10-009 Official Objectives: 2.1 – Given a scenario, configure and apply IP addressing schemes.

The correct metric is RTO (Recovery Time Objective). RTO defines the maximum acceptable time to restore services after a disruption, ensuring business continuity. For example, if the RTO is 4 hours, systems must be back online within that timeframe after an outage.

B. MTBF (Mean Time Between Failures) measures reliability by calculating the average time between hardware failures.

C. RPO (Recovery Point Objective) defines how much data loss (in terms of time, such as last backup point) is acceptable.

D. MTTR (Mean Time to Repair) measures the average time taken to fix a failure but is not a predefined business requirement like RTO.

Organizations define RTOs during disaster recovery planning to align IT recovery capabilities with business needs.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Business continuity metrics (RTO, RPO, MTBF, MTTR).

Definition of RPO:

Recovery Point Objective (RPO) is a disaster recovery metric that describes the maximum acceptable amount of data loss measured in time. It indicates the point in time to which data must be recovered to resume normal operations after a disaster.

For example, if the RPO is set to 24 hours, then the business could tolerate losing up to 24 hours' worth of data in the event of a disruption.

Why RPO is Important:

RPO is critical for determining backup frequency and helps businesses decide how often they need to back up their data. A lower RPO means more frequent backups and less potential data loss.

Comparison with Other Metrics:

MTTR (Mean Time to Repair): Refers to the average time required to repair a system or component and return it to normal operation.

RTO (Recovery Time Objective): The maximum acceptable length of time that a computer, system, network, or application can be down after a failure or disaster occurs.

MTBF (Mean Time Between Failures): The predicted elapsed time between inherent failures of a system during operation.

How RPO is Used in Disaster Recovery:

Organizations establish RPOs to ensure that they can recover data within a timeframe that is acceptable to business operations. This involves creating a backup plan that meets the RPO requirements.

Comprehensive and Detailed Explanation (aligned to N10-009):

A broadcast message is delivered to all nodes in a broadcast domain (e.g., ARP requests).

A. Unicast is one-to-one.

C. Multicast is one-to-many but only to subscribed members.

D. Anycast is one-to-one-of-many, sending to the nearest node.

References (CompTIA Network+ N10-009):

Domain: Networking Concepts — Traffic types: unicast, multicast, broadcast, anycast.