CompTIA N10-009 Actual Questions

When a DHCP server is installed and not enough IP addresses are provisioned, users may start experiencing network outages once the available IP addresses are exhausted. DHCP servers assign IP addresses to devices on the network, and if the pool of addresses is too small, new devices or those renewing their lease may fail to obtain an IP address, resulting in network connectivity issues.References: CompTIA Network+ study materials.

Network Health:

WAN 2 appears to have a lower average latency and loss percentage, which would make it the preferred WAN station for VoIP traffic. VoIP traffic requires low latency and packet loss to ensure good voice quality and reliability. WAN 1 seems to have higher RAM and processor usage, which could also affect the performance of VoIP traffic.

Here's the summary of the key metrics for WAN 1 and WAN 2 from the image provided:

WAN 1:

Uplink Speed: 10G

Total Usage: 26.969GB Up / 1.748GB Down

Average Throughput: 353MBps Up / 23.42MBps Down

Loss: 2.51%

Average Latency: 24ms

Jitter: 9.5ms

WAN 2:

Uplink Speed: 1G

Total Usage: 930GB Up / 138GB Down

Average Throughput: 12.21MBps Up / 1.82MBps Down

Loss: 0.01%

Average Latency: 11ms

Jitter: 3.9ms

For VoIP traffic, low latency and jitter are particularly important to ensure voice quality. While WAN 1 has higher bandwidth and throughput, it also has higher latency and jitter compared to WAN 2. However, WAN 2 has much lower loss, lower latency, and lower jitter, which are more favorable for VoIP traffic that is sensitive to delays and variation in packet arrival times.

Given this information, WAN 2 would generally be preferred for VoIP traffic due to its lower latency, lower jitter, and significantly lower loss percentage, despite its lower bandwidth compared to WAN 1. The high bandwidth of WAN 1 may be more suitable for other types of traffic that are less sensitive to latency and jitter, such as bulk data transfers.

Device Monitoring:

the device that is experiencing connectivity issues is the APP Server or Router 1, which has a status of Down. This means that the server is not responding to network requests or sending any data. You may want to check the physical connection, power supply, and configuration of the APP Server to troubleshoot the problem.

To change where the outside DNS records are hosted, the network administrator needs to update the NS (Name Server) records at the domain registrar. NS records specify the authoritative name servers for a domain, directing where DNS queries should be sent.

NS (Name Server) Records: These records indicate the servers that are authoritative for a domain. Changing the NS records at the registrar points DNS resolution to the new hosting provider.

SOA (Start of Authority): Contains administrative information about the domain, including the primary name server.

PTR (Pointer) Records: Used for reverse DNS lookups, mapping IP addresses to domain names.

CNAME (Canonical Name) Records: Used to alias one domain name to another, not relevant for changing DNS hosting.

Network References:

CompTIA Network+ N10-007 Official Certification Guide: Discusses DNS records, their purposes, and how to manage them.

Cisco Networking Academy: Provides training on DNS management and the role of different DNS record types.

Network+ Certification All-in-One Exam Guide: Explains DNS records and their configuration for domain management.

Introduction to Disaster Recovery Concepts:

Disaster recovery involves strategies and measures to ensure business continuity and data recovery in the event of a disaster.

Mean Time Between Failures (MTBF):

MTBF is a reliability metric used to predict the time between failures of a system during operation. It is calculated by dividing the total operational time by the number of failures.

Formula: MTBF=Total Operational TimeNumber of Failures\text{MTBF} = \frac{\text{Total Operational Time}}{\text{Number of Failures}}MTBF=Number of FailuresTotal Operational Time​

This metric helps in understanding the reliability and expected lifespan of systems and components.

Example Calculation:

If a server operates for 1000 hours and experiences 2 failures, the MTBF is: MTBF=1000 hours2=500 hours\text{MTBF} = \frac{1000 \text{ hours}}{2} = 500 \text{ hours}MTBF=21000 hours​=500 hours

Explanation of the Options:

A. MTTR (Mean Time to Repair): The average time required to repair a system after a failure.

B. MTBF (Mean Time Between Failures): The correct answer, representing the average time between failures.

C. RPO (Recovery Point Objective): The maximum acceptable amount of data loss measured in time.

D. RTO (Recovery Time Objective): The target time set for the recovery of IT and business activities after a disaster.

Conclusion:

MTBF is a crucial metric in disaster recovery and system reliability, helping organizations plan maintenance and predict system performance.

References:

CompTIA Network+ guide explaining MTBF, MTTR, RPO, and RTO concepts and their calculations (see page Ref 10†How to Use Cisco Packet Tracer).