N10-009 Networking Concepts Practice Test 3 — 15 Questions

Question 1

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

Answer

Bridge

Answer

Router

Question 2

A network engineer is designing a network and needs to ensure that broadcast traffic is contained within a single broadcast domain. Which of the following devices should be used to create these separate broadcast domains?

Accepted Answer

Router. A router operates at Layer 3 of the OSI model and does not forward broadcast frames by default, making it the correct device to segment a network into separate broadcast domains. Each interface on a router creates a distinct broadcast domain, ensuring that broadcast traffic is contained within that interface's subnet.

Answer

Hub

Answer

Bridge

Answer

Switch

Question 3

A network administrator wants to segment the network into multiple virtual LANs to reduce broadcast traffic. Which device is required to route traffic between these VLANs?

Accepted Answer

Router or Layer 3 switch. VLANs operate at Layer 2, isolating broadcast domains. To route traffic between different VLANs, a device that can forward packets based on Layer 3 IP addresses is required. A router or a Layer 3 switch (which performs hardware-based routing using ASICs) provides the necessary inter-VLAN routing functionality.

Answer

Layer 2 switch

Answer

Bridge

Answer

Hub

Question 4

A network administrator is configuring BGP between two autonomous systems. Which BGP attribute is primarily used to influence inbound traffic to a particular AS?

Accepted Answer

MED (Multi-Exit Discriminator). The Multi-Exit Discriminator (MED) is a BGP attribute used to influence inbound traffic from a neighboring AS when multiple entry points exist. A lower MED value is preferred, allowing an AS to advertise to its neighbor which path should be used to reach it, thereby influencing traffic entering the local AS.

Answer

AS_PATH

Answer

Next Hop

Answer

Local Preference

Question 5

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

Accepted Answer

It routes packets from a local subnet to destinations on other networks.. The default gateway is a router or Layer 3 device on a local subnet that serves as the next-hop IP address for packets destined to networks outside the local subnet. When a host determines that the destination IP is not on the same subnet (using its subnet mask), it forwards the packet to the default gateway's MAC address via ARP, which then routes the packet toward the remote network. Without a correctly configured default gateway, a host can only communicate within its own subnet.

Answer

It translates private IP addresses to public IP addresses.

Answer

It provides DHCP services to clients.

Answer

It performs DNS resolution for network clients.

Question 6

A network switch is experiencing a high number of collisions on a specific port. The connected device is configured for half-duplex. Which of the following is the most likely cause?

Accepted Answer

The switch port is configured for full-duplex. When a switch port is configured for full-duplex but the connected device operates in half-duplex, a duplex mismatch occurs. The switch transmits without checking for collisions (as full-duplex does not use CSMA/CD), while the half-duplex device expects to sense the carrier before sending, leading to collisions on the port. This is the most common cause of excessive collisions on a single switch port.

Answer

The cable length exceeds 100 meters

Answer

The device is using an incorrect VLAN

Answer

The switch port is configured for 1000BASE-T but the device only supports 100BASE-TX

Question 7

A router has two routes to the same destination network: one learned via OSPF with a metric of 10, and another learned via EIGRP with a composite metric of 3072. The default administrative distances are OSPF=110, EIGRP=90. Which route will be installed in the routing table?

Accepted Answer

The EIGRP route because it has a lower administrative distance. The EIGRP route is installed because administrative distance (AD) is the primary tiebreaker when multiple routing protocols provide routes to the same destination. EIGRP has a default AD of 90, which is lower than OSPF's AD of 110, so the router prefers the EIGRP route regardless of metric values. Metrics are only compared when routes come from the same protocol.

Answer

The OSPF route because it has a lower metric

Answer

Both routes will be installed for load balancing

Answer

The OSPF route because it is a link-state protocol

Question 8

A network engineer wants to segment a LAN into multiple broadcast domains without purchasing additional hardware. Which of the following technologies should be implemented?

Accepted Answer

VLANs. VLANs (Virtual Local Area Networks) allow a network engineer to logically segment a single physical LAN switch into multiple isolated broadcast domains without purchasing additional hardware. By assigning switch ports to different VLAN IDs, broadcast traffic is confined to ports within the same VLAN, effectively creating separate Layer 2 networks on the same switch infrastructure.

Answer

Subnetting

Answer

VPN

Answer

NAT

Question 9

A network administrator needs to ensure that data sent from a host arrives at the correct destination on a different network. Which of the following provides the logical address used for this purpose in IPv4?

Accepted Answer

IP address. In IPv4, the logical address used to route data between different networks is the IP address. The IP address contains a network portion that routers use to forward packets across network boundaries, ensuring the data reaches the correct destination network and host.

Answer

MAC address

Answer

Port number

Answer

Default gateway

Question 10

A network technician is configuring a small office network with two subnets: 10.0.1.0/24 and 10.0.2.0/24. Each subnet has its own switch, and both switches are connected to a router with interfaces 10.0.1.1 and 10.0.2.1. Hosts on subnet A can ping the router's interface in their subnet but cannot ping hosts on subnet B. Which of the following is the most likely cause?

Accepted Answer

IP routing is disabled on the router.. The hosts on subnet A can ping their default gateway (10.0.1.1) but cannot reach hosts on subnet B, which indicates that the router is not forwarding packets between the two directly connected subnets. This behavior is characteristic of a router with IP routing disabled, as the router will not perform inter-VLAN or inter-subnet forwarding unless the 'ip routing' command is enabled globally. Without IP routing, the router acts as a host and will only respond to traffic destined for its own interfaces, dropping any packets that require forwarding to another subnet.

Answer

The router is not configured with a routing protocol.

Answer

The hosts in subnet A have the wrong default gateway.

Answer

The switch in subnet A is blocking ICMP traffic.

Question 11

Which of the following is the primary function of a subnet mask in IPv4 networking?

Accepted Answer

It determines the network portion of an IP address. The subnet mask's primary function is to distinguish the network portion from the host portion of an IPv4 address. By applying a bitwise AND operation between the IP address and the subnet mask, the network address is derived, which is essential for routing decisions. Without this separation, devices cannot determine whether a destination is local or requires forwarding through a router.

Answer

It identifies the default gateway for a subnet

Answer

It provides encryption for data in transit

Answer

It maps IP addresses to MAC addresses

Question 12

Which of the following uniquely identifies a hardware network interface on a device?

Accepted Answer

MAC address. A MAC (Media Access Control) address is a hardware-embedded, globally unique identifier assigned to a network interface controller (NIC) by the manufacturer. It operates at Layer 2 (Data Link Layer) of the OSI model and is used for local network communication, ensuring that no two devices on the same broadcast domain have the same MAC address.

Answer

IP address

Answer

Subnet mask

Answer

Default gateway

Question 13

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).

Answer

Layer 1 – Physical

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Layer 3 – Network

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Layer 4 – Transport

Question 14

Which protocol is used to resolve a known IP address to a corresponding MAC address on a local network?

Accepted Answer

ARP. ARP (Address Resolution Protocol) is used to resolve a known IP address to its corresponding MAC address on a local network. When a host needs to send a frame to another host on the same subnet, it broadcasts an ARP request containing the target IP; the host with that IP responds with its MAC address, which is then cached for future use.

Answer

DNS

Answer

DHCP

Answer

ICMP

Question 15

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)