N10-009 Practice Test 5 — 25 Questions

Question 1

A network engineer is configuring a router to provide IPv6 addressing via SLAAC for hosts on a subnet. The ISP has delegated a prefix 2001:db8:1::/48 and requires the router to advertise a specific prefix 2001:db8:1:1::/64. Which command must be configured on the router's interface to advertise this prefix?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

ipv6 nd prefix. The 'ipv6 nd prefix' command is used on a router interface to advertise a specific IPv6 prefix in Router Advertisement (RA) messages for Stateless Address Autoconfiguration (SLAAC). This command allows the network engineer to override the default prefix derived from the interface address and explicitly advertise the delegated prefix 2001:db8:1:1::/64 as required by the ISP.

Answer

ipv6 address autoconfig

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ipv6 unicast-routing

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ipv6 dhcp server

Question 2

A network engineer plans to change the routing protocol configuration on a core router that will affect all branch connectivity. According to change management best practices, which step should the engineer perform BEFORE implementing the change?

Accepted Answer

Create a detailed rollback plan. Creating a detailed rollback plan is a fundamental change management best practice because it ensures that if the routing protocol reconfiguration (e.g., switching from EIGRP to OSPF or modifying redistribution) causes connectivity loss to all branches, the engineer can revert to the previous configuration quickly and safely. Without a rollback plan, a failed change could result in prolonged network downtime while troubleshooting from scratch, violating the principle of minimizing business impact. This step is performed before implementation to predefine the exact commands or backup configuration needed to restore the original routing state.

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Implement the change during business hours to ensure staff availability

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Notify all users after the change is complete

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Test the change directly on the production router

Question 3

A network administrator has configured a router to send syslog messages to a server with the command 'logging trap 4'. The administrator notices that the syslog server is receiving messages with severity levels 0, 1, and 2. Which of the following best explains why these messages are being received?

Accepted Answer

Syslog severity levels are reversed; lower numbers indicate higher urgency, so trap 4 includes levels 0-4.. C is correct because in syslog, severity levels are inverted: lower numbers indicate higher urgency (0=emergency, 1=alert, 2=critical). The command 'logging trap 4' sets a threshold that includes all messages with a severity level of 4 or lower (i.e., more urgent), so levels 0, 1, and 2 are included. This is defined in RFC 5424 and is standard behavior on Cisco IOS devices.

Answer

The 'trap' level indicates the minimum severity; only messages with severity 4 and above are sent.

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The router is misconfigured and sending all messages regardless of the trap level.

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The syslog server is configured to accept only levels 0-2, so it filters out the others.

Question 4

A network technician needs to discover directly connected network devices and their capabilities for documentation purposes. Which protocol should be used?

Accepted Answer

LLDP. LLDP (Link Layer Discovery Protocol) is the correct choice because it is an IEEE 802.1AB standard protocol specifically designed to discover directly connected network devices and their capabilities, such as system name, port description, VLAN information, and management addresses. Unlike proprietary protocols, LLDP operates at Layer 2 and allows any vendor's equipment to advertise and learn about neighbors without requiring IP connectivity or a management station.

Answer

SNMP

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ICMP

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ARP

Question 5

A network device receives a frame on one port and forwards it out to all other ports. The device does not examine the destination MAC address. Which type of device is being described?

Accepted Answer

Hub. A hub operates at Layer 1 (physical layer) of the OSI model and simply repeats incoming electrical or optical signals out all other ports without any processing of the frame's destination MAC address. This behavior matches the description exactly: the device receives a frame on one port and forwards it out all other ports without examining the MAC address.

Answer

Switch

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Bridge

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Router

Question 6

A company wants to allow employees to securely access internal resources (email, file servers) when working from home over the internet. Which technology should be implemented to create an encrypted tunnel between the employee's remote computer and the corporate network?

Accepted Answer

VPN concentrator. A VPN concentrator is the correct technology because it terminates VPN tunnels from remote users, creating an encrypted tunnel (using protocols like IPsec or TLS) between the employee's remote computer and the corporate network. This ensures that all traffic to internal resources such as email and file servers is securely encapsulated and protected from interception over the internet.

Answer

Firewall

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DMZ

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Intrusion detection system (IDS)

Question 7

A technician is troubleshooting intermittent connectivity issues on a fiber link between two switches. The link light on both switches is green. Which of the following tools should the technician use to further investigate the issue?

Accepted Answer

Optical power meter. The correct tool is an optical power meter because the link lights are green, indicating Layer 1 signal presence, but intermittent connectivity suggests the signal strength may be marginal or fluctuating. An optical power meter measures the exact light level in dBm to verify it falls within the receiver's sensitivity range, which a simple link LED cannot detect.

Answer

Multimeter

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Tone generator

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Cable certifier

Question 8

A network administrator needs to upgrade the backbone link between two switches to fiber optic to eliminate electromagnetic interference. The distance between the switches is 350 meters. Which transceiver type should be used?

Accepted Answer

1000BASE-SX. 1000BASE-SX (option A) is correct because it supports distances up to 550 meters over multimode fiber (MMF) at 850 nm wavelength, making it suitable for the 350-meter backbone link. It is designed to eliminate electromagnetic interference (EMI) by using fiber optic cabling, and the distance falls within its maximum reach for common multimode fiber types like OM2 or OM3.

Answer

1000BASE-LX

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1000BASE-CX

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1000BASE-T

Question 9

Which attack technique involves an attacker intercepting and potentially modifying the communication between two parties without their knowledge?

Accepted Answer

Man-in-the-middle. A man-in-the-middle (MITM) attack is correct because it specifically involves an attacker secretly intercepting and potentially altering communications between two parties who believe they are directly communicating with each other. This is achieved by the attacker inserting themselves into the communication path, often by ARP spoofing, DNS spoofing, or rogue access points, allowing them to capture, decrypt, or modify packets in transit.

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Replay attack

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Smurf attack

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Phishing

Question 10

Which of the following network topologies provides the highest level of redundancy and fault tolerance?

Accepted Answer

Mesh. A mesh topology provides the highest level of redundancy and fault tolerance because every node has a dedicated point-to-point connection to every other node. This means that if any single link or node fails, traffic can be immediately rerouted through multiple alternative paths without any single point of failure. In a full mesh, the number of links is n(n-1)/2, ensuring maximum path diversity and resilience.

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Star

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Bus

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Ring

Question 11

At which layer of the OSI model does a network device encapsulate data into frames and add source and destination MAC addresses?

Accepted Answer

Layer 2 – Data Link. The Data Link layer (Layer 2) is responsible for node-to-node communication and encapsulates packets from the Network layer into frames. It adds a header containing the source and destination MAC addresses, which are used for delivery within the same local network segment. This process is defined by IEEE 802 standards such as Ethernet (802.3) and Wi-Fi (802.11).

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Layer 1 – Physical

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Layer 3 – Network

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Layer 4 – Transport

Question 12

A company wants to ensure that only authorized users can access the internal network by requiring both a password and a one-time code from a mobile app. This is an example of:

Accepted Answer

Two-factor authentication. Two-factor authentication (2FA) requires exactly two distinct authentication factors from different categories: something you know (password) and something you have (one-time code from a mobile app). This matches the scenario precisely, as the password is a knowledge factor and the mobile app-generated code is a possession factor, satisfying the definition of 2FA.

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Single sign-on

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Biometric authentication

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Multifactor authentication with three factors

Question 13

A company wants to deploy a wireless network in an office with high-density client requirements. Which 802.11 technology allows multiple antennas to transmit multiple spatial streams to increase throughput?

Accepted Answer

MIMO (Multiple-Input Multiple-Output). MIMO (Multiple-Input Multiple-Output) is the correct technology because it uses multiple antennas at both the transmitter and receiver to send and receive multiple independent spatial streams simultaneously. This spatial multiplexing directly increases data throughput without requiring additional bandwidth or higher modulation, making it ideal for high-density client environments.

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OFDM (Orthogonal Frequency Division Multiplexing)

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DSSS (Direct Sequence Spread Spectrum)

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CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance)

Question 14

Which of the following best describes the function of a default gateway on a host?

Accepted Answer

It forwards packets destined for networks other than the local subnet. The default gateway is the router interface on the local subnet that a host uses to send packets destined for IP addresses outside its own subnet. When a host determines that the destination IP is not reachable via ARP on the local link, it forwards the packet to the default gateway's MAC address, which then routes the packet toward the remote network. This is essential for inter-subnet communication in any IP network.

Answer

It resolves domain names to IP addresses

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It assigns IP addresses to devices on the local network

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It filters traffic based on MAC addresses

Question 15

A user can ping the default gateway (192.168.1.1) but cannot access the internet (e.g., ping 8.8.8.8 fails). The user's IP is correctly configured as 192.168.1.10/24. What should the technician check next?

Accepted Answer

Check the router's default route configuration. Since the user can ping the default gateway (192.168.1.1), Layer 2 and Layer 3 connectivity within the local subnet is working, and the PC's IP configuration is correct. The failure to reach 8.8.8.8 indicates that the router does not have a valid path to external networks, which is typically provided by a default route (0.0.0.0/0). Checking the router's default route configuration is the logical next step because without it, the router cannot forward traffic destined for non-local networks.

Answer

Check the PC's DNS server settings

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Verify the subnet mask on the PC

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Examine the switch port VLAN assignment

Question 16

A user reports that their laptop is connected to the corporate Wi-Fi network but cannot access the internet. Other users in the same area are able to access the internet without issues. The laptop shows a valid IP address of 192.168.1.25/24 and the default gateway is 192.168.1.1. Which of the following should the technician check NEXT?

Accepted Answer

DNS server configuration on the laptop. Since the laptop has a valid IP address (192.168.1.25/24) and default gateway (192.168.1.1), and other users can access the internet, the issue is isolated to this laptop. A common cause is incorrect or missing DNS server configuration, which prevents domain name resolution even though IP-level connectivity exists. The technician should verify the DNS server addresses in the laptop's IPv4 settings or run 'nslookup' to confirm resolution.

Answer

DHCP server lease exhaustion

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Access point channel utilization

Answer

Switch port status on the distribution switch

Question 17

At which layer of the OSI model does the conversion of data frames into electrical signals for transmission occur?

Accepted Answer

Layer 1 (Physical). Layer 1 (Physical) is responsible for the actual transmission of raw bits over a physical medium. This includes converting data frames received from Layer 2 into electrical signals (e.g., voltage levels on copper), light pulses (fiber optic), or radio waves (wireless). The Physical layer defines the hardware specifications, such as connectors, cable types, and signaling methods like Manchester encoding or NRZ.

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Layer 2 (Data Link)

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Layer 3 (Network)

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Layer 4 (Transport)

Question 18

Users in a branch office report intermittent connectivity to the corporate data center. A technician runs a continuous ping from a workstation to the data center server and observes packet loss after the third hop. Which command should the technician run next to identify the specific router causing the issue?

Accepted Answer

tracert server_ip. The technician has already identified packet loss after the third hop using a continuous ping. The next logical step is to use `tracert` (or `traceroute` on Linux) to map the path and pinpoint which router (hop) is dropping packets. This command sends ICMP echo requests with incrementing TTL values, forcing each router along the path to reply with a Time Exceeded message, thereby revealing the specific hop where loss occurs.

Answer

ping -n 1000 server_ip

Answer

nslookup server_ip

Answer

ipconfig /all

Question 19

A company is deploying a wireless network that must support both 2.4 GHz and 5 GHz frequency bands. Which IEEE 802.11 standard supports both bands and is backward compatible with older devices?

Accepted Answer

C) 802.11n. 802.11n (Wi-Fi 4) is the correct answer because it was the first standard to natively support both 2.4 GHz and 5 GHz bands simultaneously, using MIMO (Multiple Input Multiple Output) technology. It also maintains backward compatibility with older 802.11a/b/g devices through mandatory support for legacy modulation schemes (DSSS/CCK for 2.4 GHz and OFDM for 5 GHz).

Answer

A) 802.11b

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B) 802.11g

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D) 802.11ac

Question 20

A company wants to ensure that only authorized employee computers can connect to the wired network. Each computer must be authenticated before it is granted access to the network. Which technology is designed to provide this port-based authentication?

Accepted Answer

802.1X. 802.1X is the IEEE standard for port-based Network Access Control (NAC). It uses the Extensible Authentication Protocol (EAP) over LAN (EAPoL) to authenticate a device at the switch port before granting full network access. Only after successful authentication does the switch open the port, ensuring that unauthorized computers cannot connect.

Answer

WPA2

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MAC filtering

Answer

VPN