N10-009 Timed Practice Test 1 — 10 Questions

Question 1

Which layer of the OSI model is responsible for logical addressing and routing of packets between networks?

Accepted Answer

Network layer. The Network layer (Layer 3) is responsible for logical addressing (e.g., IPv4/IPv6 addresses) and routing packets between different networks by determining the best path using routing protocols such as OSPF, BGP, or static routes. Unlike the Data Link layer, which handles physical addressing (MAC) within a single network segment, the Network layer enables end-to-end delivery across multiple hops.

Answer

Data Link layer

Answer

Transport layer

Answer

Application layer

Question 2

Users in VLAN 10 cannot obtain IP addresses from a DHCP server located in VLAN 20. The router has an ip helper-address configured on VLAN 10 interface pointing to the DHCP server. Users can ping the DHCP server IP from the router. However, users are receiving APIPA addresses. What is the most likely cause?

Accepted Answer

The DHCP server scope does not include the VLAN 10 subnet. The correct answer is B because the DHCP server must have a scope configured for the subnet of the requesting clients (VLAN 10) to assign IP addresses from that range. Since users receive APIPA addresses (169.254.x.x), the DHCP discovery process is failing, which typically occurs when the server receives the request via the ip helper-address but has no matching scope for VLAN 10. The router's ability to ping the server confirms Layer 3 reachability, isolating the issue to the server's scope configuration.

Answer

The DHCP server is not reachable from the router

Answer

The router's ip helper-address is configured incorrectly

Answer

The switch ports are not configured for VLAN 10

Question 3

Which of the following is a characteristic of a Layer 2 network switch?

Accepted Answer

Uses MAC addresses to make forwarding decisions. A Layer 2 network switch operates at the Data Link layer of the OSI model and uses MAC addresses to make forwarding decisions. It examines the destination MAC address in an Ethernet frame and consults its MAC address table to determine the appropriate port to forward the frame, enabling efficient local area network communication.

Answer

Makes forwarding decisions based on IP addresses

Answer

Can route traffic between different VLANs without a router

Answer

Provides Network Address Translation (NAT)

Question 4

Which of the following network devices operates primarily at Layer 2 of the OSI model and uses MAC addresses to forward data?

Accepted Answer

Switch. A switch operates primarily at Layer 2 (Data Link layer) of the OSI model, forwarding frames based on destination MAC addresses. It builds a MAC address table by learning source MAC addresses from incoming frames and uses this table to make forwarding decisions, reducing collision domains and improving network efficiency.

Answer

Hub

Answer

Router

Answer

Firewall

Question 5

Which of the following is a characteristic of UDP when compared to TCP?

Accepted Answer

C) UDP has lower overhead due to minimal header. UDP (User Datagram Protocol) has a minimal 8-byte header compared to TCP's 20-byte header, resulting in lower overhead and faster transmission. Unlike TCP, UDP does not provide reliability, flow control, or error recovery, making it ideal for real-time applications like VoIP or video streaming where speed is prioritized over guaranteed delivery.

Answer

A) UDP uses sequence numbers for ordering

Answer

B) UDP provides reliable data delivery

Answer

D) UDP requires a three-way handshake to establish a connection

Question 6

Which of the following IPv6 addresses is a valid link-local address?

Accepted Answer

fe80::1. Option A is correct because link-local addresses in IPv6 always start with the prefix fe80::/10, and fe80::1 is a valid example. These addresses are automatically configured on interfaces for local link communication and are not routable beyond the local network segment.

Answer

2001:db8::1

Answer

ff02::1

Answer

10.0.0.1

Question 7

Which of the following security mechanisms requires a user to authenticate before gaining access to the wired network at a switch port?

Accepted Answer

802.1X. 802.1X is a port-based Network Access Control (NAC) standard (IEEE 802.1X) that requires a user or device to authenticate via an authentication server (e.g., RADIUS) before the switch port transitions from an unauthorized to an authorized state, allowing full network access. It uses Extensible Authentication Protocol (EAP) over LAN (EAPoL) to carry authentication messages between the supplicant (client), authenticator (switch), and authentication server. This ensures that only authenticated users can access the wired network at the switch port level.

Answer

Port security

Answer

ACL

Answer

MAC authentication

Question 8

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.

Answer

Star

Answer

Bus

Answer

Ring

Question 9

Which of the following protocols is used to automatically assign IP addresses to devices on a network?

Accepted Answer

B) DHCP. DHCP (Dynamic Host Configuration Protocol) is the correct answer because it is specifically designed to automatically assign IP addresses and other network configuration parameters (such as subnet mask, default gateway, and DNS servers) to devices on a network. When a client device connects, it sends a DHCP Discover broadcast, and the DHCP server responds with an Offer, followed by a Request and Acknowledgment (DORA process), enabling plug-and-play connectivity.

Answer

A) DNS

Answer

C) ARP

Answer

D) ICMP

Question 10

An organization uses OSPF as its interior gateway protocol in a multi-area design. After a core router failure, the network takes several seconds to reconverge. Which technology can be implemented to improve convergence speed?

Accepted Answer

Configure BFD (Bidirectional Forwarding Detection). BFD provides sub-second failure detection times (as low as 50 ms) independent of the routing protocol, allowing OSPF to reconverge much faster than relying on its default dead timer intervals. By detecting link failures in milliseconds, BFD triggers OSPF to immediately recalculate routes, drastically reducing the convergence delay after a core router failure.

Answer

Implement LSA throttling

Answer

Enable OSPF fast hello timers

Answer

Convert all areas to stub areas