Pass the CompTIA Network+ N10-009 Questions and answers with ExamsMirror

Jumbo frames are Ethernet frames with a payload greater than the standard 1,500 bytes. Using jumbo frames reduces the number of frames transmitted over the network, thereby reducing the overhead associated with frame headers and processing. The document explains:

“Jumbo frames are used in storage networks to reduce device overhead by lowering the number of frames required for data transfer, which can increase overall throughput and performance.”

Network Functions Virtualization (NFV): NFV is a technology that virtualizes network services like routing, firewalls, and load balancers. It allows these services to run on virtual machines rather than requiring dedicated hardware. This is ideal for remote branch locations where deploying physical devices is costly and complex.

VRF (B): Virtual Routing and Forwarding is used for segmenting routing tables but does not virtualize services.

VLAN (C): Virtual Local Area Networks help segregate broadcast domains but are unrelated to virtualizing network functions.

VPC (D): Virtual Private Cloud is used for cloud computing but does not pertain to virtualizing network services.

X.509 certificates are most commonly associated with Public Key Infrastructure (PKI). These certificates are used for a variety of security functions, including digital signatures, encryption, and authentication.

PKI: X.509 certificates are a fundamental component of PKI, used to manage encryption keys and authenticate users and devices.

Digital Certificates: They are used to establish secure communications over networks, such as SSL/TLS for websites and secure email communication.

Authentication and Encryption: X.509 certificates provide the means to securely exchange keys and verify identities in various applications, ensuring data integrity and confidentiality.

Network References:

CompTIA Network+ N10-007 Official Certification Guide: Covers PKI and the role of X.509 certificates in network security.

Cisco Networking Academy: Provides training on PKI, certificates, and secure communications.

Network+ Certification All-in-One Exam Guide: Explains PKI, X.509 certificates, and their applications in securing network communications.

Private VLANs (PVLANs) are used to segment devices on the same subnet and switch so they cannot communicate with each other, while still accessing a shared resource like a router or gateway. This is often used in shared hosting or DMZ environments.

A. ACLs (Access Control Lists) control traffic between networks, not within the same VLAN.

B. Trunking carries multiple VLANs between switches but does not isolate devices.

C. Port security limits MAC addresses per port but doesn’t isolate communication between ports.

???? Reference:

CompTIA Network+ N10-009 Official Objectives: 3.4 – Compare and contrast access control methods.

The correct answer is Modify the CNAME record because a CNAME (Canonical Name) record maps one domain name (alias) to another domain name. If a user enters www.abc.com but is redirected to www.cba.com, it is likely that the DNS configuration includes an incorrect CNAME entry pointing abc.com to cba.com. Updating or correcting the CNAME record ensures the alias resolves to the intended host.

According to CompTIA Network+ (N10-009) objectives covering DNS record types, a CNAME record is used to alias one domain name to another, commonly for load balancing, CDN services, or website redirection.

A PTR record (Option B) is used for reverse DNS lookups (IP address to hostname) and does not control forward name resolution for websites. NTP settings (Option C) are used for time synchronization and have no impact on DNS resolution. A TXT record (Option D) stores descriptive text information (such as SPF, DKIM, or domain verification data) and does not affect website redirection.

Therefore, correcting the CNAME record resolves the issue and ensures users reach the correct website.

The correct choice is B. Using a single public IP. PAT (Port Address Translation) is a form of NAT that allows many internal private IP addresses to share one public IP address by tracking sessions with port numbers. This is one of the most common edge-network designs for homes, small offices, and many enterprise branch environments.

The reason PAT is so useful is that it conserves public IPv4 addresses. Internal hosts keep their private addressing, and when they access external resources, the firewall or router translates those connections so they appear to come from one public address, while still keeping each session unique through port mapping.

The other options are unrelated to PAT’s primary purpose. BGP is a routing protocol for route exchange between networks. Redundant ISPs deal with resiliency and multihoming, not port-based address translation. A dual-stack IP scheme means running IPv4 and IPv6 together, which is separate from the NAT/PAT function.

This question is really asking what situation most naturally calls for PAT. When an organization wants multiple internal devices to reach the internet without assigning each device its own public IPv4 address, PAT is the standard solution. That makes using a single public IP the best answer.

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

SSH provides secure, scriptable remote access used by automation/orchestration tools (e.g., leveraging CLI, NETCONF over SSH, or Ansible modules) to push configurations at scale.

A. RDP is primarily for Windows GUI sessions and is not commonly used for network device automation.

B. Telnet can be scripted but is insecure (plaintext); modern best practice is to use SSH.

D. GUI access is typically manual and not ideal for scalable, repeatable automation.

References (CompTIA Network+ N10-009):

Domain: Network Operations — Configuration management, automation/orchestration, secure management protocols (SSH vs. Telnet), change at scale.

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Traffic analysis involves monitoring and inspecting network traffic flows to detect unusual patterns, such as a workstation sending large volumes of outbound SMTP (spam). This process enables identification of malware as the root cause.

B. Availability monitoring checks uptime but doesn’t diagnose spam traffic.

C. Baseline metrics show normal usage but don’t pinpoint infected hosts.

D. Network discovery identifies devices, not malicious traffic flows.

References (CompTIA Network+ N10-009):

Domain: Network Security — Traffic analysis, malware detection, identifying compromised hosts.

To prioritize traffic and utilize a constrained link more effectively, the engineer should implement QoS (Quality of Service). QoS is a set of mechanisms that classifies and marks traffic (for example, voice, video, business-critical apps) and then applies queuing and scheduling behaviors to ensure important traffic receives preferential treatment during congestion. Network+ objectives commonly connect QoS to supporting real-time applications (VoIP/video) by reducing latency, jitter, and packet loss, while preventing less critical traffic (bulk transfers, updates) from consuming all available bandwidth. Techniques can include traffic classification, DSCP marking, priority queuing, and traffic shaping/policing.

A CDN improves content delivery by caching closer to users, but it doesn’t provide link-level prioritization for all traffic types. A VPN provides secure tunneling/encryption, not prioritization. TTL (Time To Live) is an IP header value used to prevent routing loops by limiting packet lifespan; it does not manage bandwidth or prioritize flows. QoS is the standard solution when the goal is to control how bandwidth is allocated under load and to ensure critical services remain performant.

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Disabling unused ports prevents unauthorized access and reduces the attack surface by ensuring that no inactive or unmonitored entry points are available for exploitation. Changing default passwords is critical for security because default credentials are widely known and can easily be exploited by attackers. These techniques are fundamental steps in hardening devices against unauthorized access and ensuring network security. References: CompTIA Network+ Exam Objectives and official study guides.

ESP (Encapsulating Security Payload) is an IPsec protocol that provides encryption, integrity, and authentication for data inside a VPN tunnel. It ensures that all tunneled traffic is encrypted.

B. SSH secures remote terminal sessions, not site-to-site VPN tunnels.

C. GRE (Generic Routing Encapsulation) provides encapsulation but does not encrypt data.

D. IKE (Internet Key Exchange) negotiates keys and establishes the IPsec tunnel but does not encrypt the payload itself.

References (CompTIA Network+ N10-009):

Domain: Network Security — VPN protocols, IPsec (AH vs. ESP), encryption in transit.

For 45 hosts, the minimum subnet size must allow at least 46 usable addresses (1 each for network and broadcast addresses).

A /26 subnet provides 64 addresses, 62 usable — suitable.

A /27 subnet gives only 30 usable — insufficient.

A /25 offers 126 usable — more than needed.

A /28 provides just 14 — too small.

So, the most efficient subnet with minimal wastage is /26.

From Andrew Ramdayal’s guide:

“When designing subnets, always choose the smallest subnet mask that still accommodates all hosts. A /26 provides 62 usable host addresses, suitable for networks with about 50 hosts.”

The correct answer is D. DHCP reservation. In a network environment, printers are typically configured to use a consistent IP address so that client devices can reliably locate them. After a power outage, network devices such as printers may reboot and request a new IP address from the DHCP server. If the printer was previously assigned a dynamic IP address, it may now receive a different address, causing users’ systems to lose connectivity because they are still trying to print to the old IP.

A DHCP reservation ensures that a specific device (identified by its MAC address) always receives the same IP address from the DHCP server. This combines the convenience of DHCP with the stability of static addressing, which is ideal for shared resources like printers.

The other options are incorrect for this scenario. DoH (DNS over HTTPS) secures DNS queries and is unrelated to IP address assignment. SLAAC (Stateless Address Autoconfiguration) is used for IPv6, not IPv4 environments. APIPA (Automatic Private IP Addressing) assigns a link-local address when DHCP fails, but it does not provide consistent or routable addressing suitable for shared printers.

Therefore, configuring a DHCP reservation ensures consistent network access to the printer after power disruptions.

RPO (Recovery Point Objective) describes a data recovery goal by defining the maximum acceptable amount of data loss measured in time. For example, an RPO of 4 hours means the organization must be able to restore data to a point no more than four hours before the outage—so backups, replication, or snapshots must occur frequently enough to meet that target. In Network+ (N10-009) operations objectives, disaster recovery and business continuity concepts include understanding recovery metrics and how they influence backup strategies, replication design, and service resilience planning. RPO specifically answers: “How much data can we afford to lose?”

By contrast, MTBF (Mean Time Between Failures) is a reliability metric describing how often failures occur. MTTR (Mean Time To Repair/Recover) measures how long it takes to restore a system after failure, which is more aligned with service restoration time rather than data loss. BCP (Business Continuity Plan) is the overall plan/process for keeping critical business functions running during disruptions; it is not a single data recovery metric. Therefore, RPO is the correct term for a data recovery goal.

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