N10-009 Practice Test 10 — 10 Questions

Question 1

Which device operates at Layer 1 (Physical) of the OSI model and regenerates electrical signals to extend the distance of a network segment?

Accepted Answer

Hub. A hub operates at Layer 1 (Physical) of the OSI model. It receives incoming electrical signals on one port and regenerates (repeats) those signals out to all other ports, effectively extending the physical reach of a network segment. Unlike switches or routers, it performs no frame inspection or forwarding decisions.

Answer

Switch

Answer

Router

Answer

Bridge

Question 2

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?

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

Answer

ipv6 unicast-routing

Answer

ipv6 dhcp server

Question 3

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.

Answer

Implement the change during business hours to ensure staff availability

Answer

Notify all users after the change is complete

Answer

Test the change directly on the production router

Question 4

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.

Answer

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

Answer

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

Question 5

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

Answer

ICMP

Answer

ARP

Question 6

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 7

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

Answer

DMZ

Answer

Intrusion detection system (IDS)

Question 8

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

Answer

Tone generator

Answer

Cable certifier

Question 9

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

Answer

1000BASE-CX

Answer

1000BASE-T

Question 10

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.

Answer

Replay attack

Answer

Smurf attack

Answer

Phishing