N10-009 Practice Test 31 — 15 Questions

Question 1

Which device is used to connect two different network segments and makes forwarding decisions based on IP addresses?

Accepted Answer

Router. A router is the correct device because it operates at Layer 3 (Network layer) of the OSI model and makes forwarding decisions based on destination IP addresses. It connects two different network segments (subnets) and uses routing tables to determine the best path for packet delivery, often employing protocols like OSPF or BGP.

Answer

Switch

Answer

Hub

Answer

Bridge

Question 2

A network administrator needs to remotely manage multiple routers and switches. The management traffic must be encrypted. Which protocol should be used for the remote terminal sessions?

Accepted Answer

SSH. SSH (Secure Shell) encrypts all traffic, including authentication credentials and session data, making it the correct choice for securely managing routers and switches over a network. Telnet transmits everything in plaintext, while SNMP and HTTP lack the interactive encrypted terminal session required for remote CLI management.

Answer

Telnet

Answer

SNMP

Answer

HTTP

Question 3

A network device receives a frame and forwards it based on the destination MAC address. The device does not modify the frame and only floods unknown unicast frames. At which layer of the OSI model does this device operate?

Accepted Answer

Layer 2. This device operates at Layer 2 (Data Link Layer) because it forwards frames based on the destination MAC address, does not modify the frame, and floods unknown unicast frames. These behaviors are characteristic of a transparent bridge or switch, which uses a MAC address table to make forwarding decisions without examining IP addresses or modifying the frame. Layer 2 devices do not perform routing or alter the frame's content, distinguishing them from Layer 3 routers.

Answer

Layer 1

Answer

Layer 3

Answer

Layer 4

Question 4

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

Accepted Answer

fe80::1. 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 5

A network engineer is designing a data center network and needs to ensure high availability for the core switches. Which technology allows multiple physical switches to be combined into a single logical switch to simplify management and improve redundancy?

Accepted Answer

Switch stacking. Switch stacking combines multiple physical switches into a single logical unit, sharing a common control plane and management interface. This simplifies configuration and provides redundancy because if one switch in the stack fails, the remaining switches continue forwarding traffic without requiring STP convergence.

Answer

Spanning Tree Protocol (STP)

Answer

EtherChannel

Answer

Virtual Router Redundancy Protocol (VRRP)

Question 6

A security auditor recommends implementing a solution that authenticates users and devices before granting network access, regardless of the physical port they connect to. Which technology should be deployed?

Accepted Answer

802.1X. 802.1X is the correct technology because it provides port-based network access control (PNAC) that authenticates users and devices before granting network access, regardless of the physical port they connect to. It uses the Extensible Authentication Protocol (EAP) over LAN (EAPoL) to communicate with a RADIUS server, ensuring that only authenticated endpoints are allowed on the network. This meets the auditor's requirement for authentication at the port level, independent of the switch port used.

Answer

Port security

Answer

VLAN hopping

Answer

DHCP snooping

Question 7

A network technician is explaining the OSI model to a junior technician. The technician mentions that the Transport layer is responsible for end-to-end communication and data segmentation. Which protocol operates at the Transport layer?

Accepted Answer

TCP. TCP (Transmission Control Protocol) operates at Layer 4 (Transport) of the OSI model, providing reliable, connection-oriented end-to-end communication and data segmentation with sequencing and acknowledgment. It ensures data is delivered error-free and in order, directly fulfilling the described responsibilities.

Answer

IP

Answer

Ethernet

Answer

HTTP

Question 8

Two switches are connected via a trunk link configured with allowed VLANs 10, 20, and 30. Hosts on VLAN 20 can communicate across the trunk, but hosts on VLAN 30 cannot. Which of the following is the most likely cause?

Accepted Answer

D. The most likely cause is that VLAN 30 is only created on one switch. For a trunk to forward frames for a VLAN, that VLAN must exist (be created) on both switches. If VLAN 30 is only configured on one switch, the other switch will drop frames from VLAN 30, preventing communication. This explains why VLAN 20 works (exists on both) and VLAN 30 does not.

Answer

A

Answer

B

Answer

C

Question 9

A network technician installs a new 802.3at (PoE+) access point in a warehouse. The AP is connected via a 200-foot Cat5e cable to a switch that only supports 802.3af (PoE). The AP powers on but experiences intermittent connectivity drops. What is the most likely cause?

Accepted Answer

The AP is not receiving enough power from the switch. The switch only supports 802.3af (PoE), which provides a maximum of 15.4 watts per port, while the 802.3at (PoE+) access point requires up to 25.5 watts to operate reliably. The AP powers on because it can negotiate 802.3af power, but under load (e.g., transmitting at higher power or using multiple radios), it draws more current than the switch can supply, causing voltage droop and intermittent resets or link drops. This is a classic power budget mismatch scenario.

Answer

The cable length exceeds the maximum allowed for PoE

Answer

Duplex mismatch between the AP and the switch

Answer

Radio frequency interference from warehouse equipment

Question 10

A network administrator needs to ensure that network device configurations are automatically backed up to a central server. Which protocol is commonly used for secure file transfer of configurations?

Accepted Answer

SFTP. SFTP (SSH File Transfer Protocol) is the correct choice because it provides encrypted, secure file transfers over an SSH session, making it ideal for backing up sensitive network device configurations to a central server. Unlike TFTP or FTP, SFTP ensures both authentication and data confidentiality, which is critical for network operations.

Answer

TFTP

Answer

FTP

Answer

HTTP

Question 11

At which OSI layer does a router primarily operate to make forwarding decisions based on IP addresses?

Accepted Answer

Layer 3 (Network). A router primarily operates at Layer 3 (Network) of the OSI model because it uses logical IP addresses (e.g., IPv4 or IPv6) to make forwarding decisions. The router examines the destination IP address in the packet header, performs a longest-prefix match against its routing table, and determines the next-hop interface. This layer is responsible for end-to-end delivery and path selection across multiple networks.

Answer

Layer 1 (Physical)

Answer

Layer 2 (Data Link)

Answer

Layer 4 (Transport)

Question 12

Match each network device to its primary function.

Accepted Answer

Router: Connects multiple networks and routes data packets between them.. The correct matches are: Router → routes between networks, Switch → forwards within a LAN using MAC, Firewall → filters traffic by rules, Access Point → wireless connectivity. Common confusions include mixing router and modem functions, and hub vs switch.

Answer

Modem: Connects multiple networks and routes data packets between them.

Answer

Hub: Connects devices within a single network and forwards data based on MAC addresses.

Question 13

A network administrator wants to monitor network devices using SNMP. The security policy requires both authentication and encryption of SNMP packets. Which SNMP version and security level should be configured?

Accepted Answer

SNMPv3 with authPriv. SNMPv3 is the only version that supports both authentication and encryption. The security level 'authPriv' enables both authentication (via HMAC-MD5 or HMAC-SHA) and encryption (via CBC-DES or CFB128-AES), meeting the policy requirement. SNMPv1 and SNMPv2c use only plaintext community strings with no security, while 'authNoPriv' provides authentication without encryption.

Answer

SNMPv2c with a community string

Answer

SNMPv3 with authNoPriv

Answer

SNMPv1 with a community string

Question 14

A user reports that they cannot access any network resources. The technician checks the IP configuration and sees that the workstation has an IP address of 169.254.1.5. What is the most likely cause?

Accepted Answer

The DHCP server is unavailable. The IP address 169.254.1.5 is an Automatic Private IP Addressing (APIPA) address (169.254.0.0/16 range), which Windows assigns when a DHCP client fails to receive a lease from a DHCP server. Since the workstation cannot obtain a valid IP configuration, it cannot communicate with any network resources, confirming that the DHCP server is unavailable.

Answer

The DNS server is down

Answer

The default gateway is incorrect

Answer

The subnet mask is mismatched

Question 15

Which of the following IP addresses is a private IP address as defined by RFC 1918?

Accepted Answer

192.168.1.1. (192.168.1.1) is correct because RFC 1918 reserves the 192.168.0.0/16 block (192.168.0.0 – 192.168.255.255) for private use within local networks. This address is not routable on the public internet, making it suitable for internal LAN addressing.

Answer

169.254.1.1

Answer

172.32.1.1

Answer

172.15.1.1