N10-009 Practice Test 22 — 15 Questions

Question 1

Which of the following best describes the primary function of the transport layer in the OSI model?

Accepted Answer

Providing end-to-end communication and data flow control. The transport layer (Layer 4) is responsible for end-to-end communication between hosts, including segmentation, reassembly, and flow control. Protocols like TCP use windowing and acknowledgments to manage data flow, ensuring reliable delivery. This distinguishes it from lower layers that handle routing or physical signaling.

Answer

Routing packets across networks

Answer

Encoding data into electrical signals

Answer

Determining the best path for data transmission

Question 2

A security analyst notices that an attacker is sending crafted packets with overlapping IP fragments to a target server, causing the server to crash. Which type of attack is described?

Accepted Answer

Teardrop attack. This is a Teardrop attack, which exploits a vulnerability in the IP fragmentation reassembly process. The attacker sends a series of fragmented IP packets with intentionally overlapping fragment offsets, causing the target system to miscalculate the size of the reassembled packet, leading to a buffer overflow and system crash. This attack specifically targets the IP stack's handling of fragment offset fields in the IP header.

Answer

Smurf attack

Answer

Ping flood

Answer

SYN flood

Question 3

A network administrator is configuring a new switch for management access via SSH. Which step must be performed FIRST?

Accepted Answer

Configure an IP address on the management VLAN.. Before SSH can function, the switch must have an IP address assigned to the management VLAN (typically VLAN 1 or a dedicated management VLAN) so that the switch is reachable over the network. Without this IP configuration, the switch cannot establish the TCP/IP connectivity required for SSH sessions, making it the foundational step that must be performed first.

Answer

Generate RSA key pair.

Answer

Configure a VTY password.

Answer

Enable SSH version 2.

Question 4

A network technician is explaining the role of a network switch to a new employee. Which of the following best describes the primary function of a switch in a local area network?

Accepted Answer

It forwards data based on MAC addresses.. A network switch operates at Layer 2 of the OSI model and uses MAC addresses to make forwarding decisions. When a frame arrives, the switch examines the destination MAC address, looks it up in its MAC address table, and forwards the frame only to the port associated with that address, reducing collision domains and improving network efficiency.

Answer

It forwards data based on IP addresses.

Answer

It connects different networks and performs routing.

Answer

It amplifies and repeats the signal to all ports.

Question 5

A network switch forwards frames based on which address?

Accepted Answer

MAC address. A network switch operates at Layer 2 (Data Link Layer) of the OSI model and uses MAC addresses to make forwarding decisions. When a frame arrives, the switch examines the destination MAC address, looks it up in its MAC address table (CAM table), and forwards the frame only to the port associated with that MAC address, reducing collision domains and improving network efficiency.

Answer

IP address

Answer

Port number

Answer

Domain name

Question 6

A network administrator needs to ensure that in the event of a switch failure, the switch can be replaced and brought online with minimal downtime. Which of the following tasks should the administrator perform regularly?

Accepted Answer

Back up the configuration files of all switches. Regularly backing up the configuration files of all switches ensures that when a failed switch is replaced, the exact configuration can be restored quickly, minimizing downtime. This is a core best practice in network operations because a replacement switch typically ships with factory defaults and requires the original configuration to resume normal operations. Without a recent backup, the administrator would have to reconfigure the switch manually, leading to extended outage and potential human error.

Answer

Perform a firmware upgrade on all switches

Answer

Monitor the switch's CPU utilization

Answer

Create a network performance baseline

Question 7

A network administrator needs to monitor bandwidth utilization on a router interface in real time. Which of the following protocols is best suited for this purpose?

Accepted Answer

SNMP polling. SNMP polling is the best choice for real-time bandwidth monitoring because it allows the network management system (NMS) to actively query the router's interface MIB (e.g., ifInOctets, ifOutOctets) at short intervals, calculating utilization from the delta between successive polls. This provides near-real-time data without waiting for unsolicited events, making it ideal for live dashboards and threshold alerts.

Answer

Syslog

Answer

NetFlow

Answer

CDP

Question 8

A network engineer is designing a new switched network and needs to ensure that broadcast traffic from one department does not reach another department's workstations. The engineer plans to use VLANs. Which of the following must be configured on the switches to isolate broadcast domains as intended?

Accepted Answer

Assign each department's workstations to a unique VLAN and configure their switch ports as access ports in that VLAN.. VLANs segment a switched network into separate broadcast domains at Layer 2. By assigning each department's workstations to a unique VLAN and configuring their switch ports as access ports in that VLAN, broadcast traffic from one VLAN is confined to that VLAN and cannot reach workstations in another VLAN. This achieves the isolation required without additional filtering devices.

Answer

Configure all switch ports as trunk ports and use VLAN 1 for all departments.

Answer

Place all workstations in the same VLAN and use a firewall to filter broadcast traffic between departments.

Answer

Configure each switch port as a trunk and use a different native VLAN for each department.

Question 9

A company is deploying a new wireless network for a small office. The network will consist of three access points. The IT manager wants the APs to automatically coordinate radio frequency settings and client roaming without a dedicated controller. Which technology should be implemented?

Accepted Answer

Cloud-managed access points. Cloud-managed access points (APs) are the correct choice because they can automatically coordinate radio frequency (RF) settings and client roaming without a dedicated on-premises controller. The cloud-based management platform handles channel selection, power adjustment, and fast roaming (e.g., 802.11r/k/v) by communicating with each AP over the internet, making it ideal for a small office with only three APs.

Answer

Mesh network

Answer

Controller-based wireless

Answer

Standalone APs

Question 10

A technician is troubleshooting an intermittent connectivity issue between two switches connected by a fiber optic cable. The link status shows up/down flapping. The technician checks the optical power levels and finds they are within acceptable range. Which of the following is the most likely cause?

Accepted Answer

Dirty fiber connectors. Intermittent link flapping with acceptable optical power levels strongly indicates a physical-layer issue that is not related to signal strength. Dirty fiber connectors cause intermittent signal degradation due to scattering and absorption of light, leading to CRC errors and link flaps even when average power appears normal. Cleaning the connectors is the standard first step in such scenarios.

Answer

Duplex mismatch

Answer

Speed mismatch

Answer

VLAN mismatch

Question 11

Which transport layer protocol is used by VoIP and streaming video because it provides low latency and does not require retransmission?

Accepted Answer

UDP. VoIP and streaming video use UDP (User Datagram Protocol) because it is connectionless and provides low-latency transmission without retransmission of lost packets. This is critical for real-time applications where a slight delay is more disruptive than occasional packet loss.

Answer

TCP

Answer

ICMP

Answer

IGMP

Question 12

A network engineer is deploying a wireless network using 802.11ac. To allow clients to roam between access points without re-authenticating to the authentication server, which IEEE standard should be implemented?

Accepted Answer

802.11r. 802.11r, also known as Fast BSS Transition (FT), enables clients to roam between access points using a cached Pairwise Master Key (PMK) without requiring a full 802.1X/EAP re-authentication with the RADIUS server. This reduces roaming latency to under 50 ms, which is critical for voice and video applications.

Answer

802.1X

Answer

802.11i

Answer

802.11e

Question 13

A network technician is troubleshooting an intermittent connectivity issue between two switches connected via fiber optic cable. The link status shows up/down flapping. The technician checks the optical power levels and finds they are within acceptable range. Which of the following is the most likely cause?

Accepted Answer

Dirty fiber connectors. Dirty fiber connectors cause intermittent connectivity by scattering or absorbing light, leading to bit errors and link flaps even when average optical power levels appear within acceptable range. The flapping occurs because transient contaminants (e.g., dust or oil) momentarily disrupt the optical signal, triggering link down events that recover when the connector is jostled or the contaminant shifts. Since the power meter measures average power, it may not detect brief attenuation spikes caused by dirt.

Answer

Electromagnetic interference

Answer

Incorrect VLAN configuration

Answer

Duplex mismatch

Question 14

A network administrator needs to allow multiple VLANs to traverse a single link between two switches. Which configuration must be applied on the switch ports?

Accepted Answer

Trunk port. A trunk port is configured to carry traffic for multiple VLANs over a single link by tagging frames with IEEE 802.1Q VLAN identifiers. This allows the switch to distinguish which VLAN each frame belongs to, enabling inter-switch VLAN connectivity without requiring separate physical links per VLAN.

Answer

Access port

Answer

Hybrid port

Answer

Routed port

Question 15

An organization wants to implement a security solution that uses a cloud-based service to inspect all incoming web traffic for malware and policy violations before it reaches the internal network. This type of solution is known as a:

Accepted Answer

Secure web gateway (SWG). A Secure Web Gateway (SWG) is a cloud-based security solution that inspects all outbound and inbound web traffic for malware, policy violations, and data loss. It operates at the application layer, typically using proxy-based or API-based inspection to enforce security policies before traffic reaches the internal network. This matches the requirement for a cloud service that inspects incoming web traffic for malware and policy violations.

Answer

Web application firewall (WAF)

Answer

Intrusion detection system (IDS)

Answer

VPN concentrator