N10-009 Network Implementation Practice Test 6 — 15 Questions

Question 1

A network administrator needs to power IP phones and wireless access points through the Ethernet cable. Which standard should be supported?

Accepted Answer

802.3af. The 802.3af standard, also known as Power over Ethernet (PoE), delivers up to 15.4 watts of DC power over twisted-pair Ethernet cabling. This allows devices like IP phones and wireless access points to receive both data and power through a single Ethernet cable, eliminating the need for separate power supplies.

Answer

802.11ac

Answer

802.1X

Answer

802.3ab

Question 2

A network technician configures an 802.1Q trunk link between two switches. After the configuration, VLAN 20 traffic is not passing across the trunk, although VLAN 10 traffic works fine. The technician verifies that both switches have VLAN 20 created and that the trunk is up. What is the most likely cause?

Accepted Answer

VLAN 20 is not included in the allowed VLAN list on the trunk.. The most likely cause is that VLAN 20 is not included in the allowed VLAN list on the trunk. By default, an 802.1Q trunk allows all VLANs, but if the allowed VLAN list has been manually configured or pruned, VLAN 20 may have been excluded. Since VLAN 10 works, the trunk is operational, and both switches have VLAN 20 created, the issue is specifically that the trunk is not permitting VLAN 20 traffic.

Answer

The native VLAN is mismatched between the switches.

Answer

The trunk port is set to dynamic desirable mode.

Answer

The encapsulation type is ISL instead of 802.1Q.

Question 3

A new switch is installed in a remote wiring closet. It has been configured with a management IP address of 10.1.2.50/24. The switch is connected via a trunk to the distribution switch, and the management station (10.1.1.0/24) is on a different subnet. The switch cannot be pinged from the management station. The distribution switch has routing to the 10.1.2.0/24 subnet. What is the most likely cause?

Accepted Answer

The default gateway is not configured on the new switch.. The management station is on subnet 10.1.1.0/24, while the switch's management IP is 10.1.2.50/24. For the switch to reply to pings from a different subnet, it must have a default gateway configured so it knows where to send return traffic. Without a default gateway, the switch will only respond to traffic on its local subnet, making it unreachable from the management station.

Answer

The management VLAN is not allowed on the trunk.

Answer

The switch port to the distribution switch is in access mode.

Answer

The management IP is configured on the wrong VLAN.

Question 4

A network administrator wants to allow wireless clients to seamlessly roam between access points without re-authenticating to the RADIUS server for each transition. Which IEEE standard should be implemented?

Accepted Answer

802.11r. 802.11r, also known as Fast BSS Transition (FT), enables wireless clients to roam between access points without re-authenticating to the RADIUS server by using a cached Pairwise Master Key (PMK) and performing a faster, over-the-air or over-the-DS key exchange. This reduces the time required for roaming handoffs, which is critical for real-time applications like VoIP.

Answer

802.11k

Answer

802.11w

Answer

802.1X

Question 5

A network engineer needs to add a new switch to an existing network. The switch must be configured to support VLANs and trunking. The engineer connects the switch to the existing network via a trunk port. After configuration, the VLANs on the new switch are not receiving traffic from the core network. The core switch shows the trunk is up but no VLANs are allowed. What is the most likely cause?

Accepted Answer

The allowed VLAN list on the trunk does not include the desired VLANs. The core switch shows the trunk is up but no VLANs are allowed, which directly indicates that the allowed VLAN list on the trunk port does not include the desired VLANs. By default, a trunk port permits all VLANs, but if an administrator explicitly restricts the allowed VLAN list (e.g., with the 'switchport trunk allowed vlan' command), only those VLANs are forwarded. Since the new switch is not receiving traffic, the core switch's trunk likely has an empty or incorrect allowed VLAN list, preventing the desired VLAN traffic from crossing the trunk.

Answer

The native VLAN mismatch

Answer

The trunk encapsulation is not set to 802.1Q

Answer

The switch port mode is set to access

Question 6

A network technician is installing a new wireless access point in a warehouse. The AP requires PoE+ (802.3at) for full operation. The technician connects the AP using a Cat5e cable run of 200 feet to a switch that only supports 802.3af (PoE). The AP powers on but has intermittent connectivity issues. What is the most likely cause?

Accepted Answer

The switch does not support the required PoE standard. The switch only supports 802.3af (PoE), which provides up to 15.4W per port, while the AP requires 802.3at (PoE+) for full operation, which supplies up to 30W. Although the AP powers on, it may not receive sufficient power to operate all radios or features, leading to intermittent connectivity issues. The cable length of 200 feet is within the 100-meter (328-foot) limit for Cat5e, so length is not the problem.

Answer

The cable length exceeds the maximum for PoE

Answer

The AP is experiencing interference from metal racks

Answer

The AP is configured with the wrong SSID

Question 7

A network administrator needs to connect two buildings 2 km apart using single-mode fiber. Which transceiver type should be used?

Accepted Answer

1000BASE-LX. 1000BASE-LX (Long Wavelength) operates at 1310 nm over single-mode fiber and supports distances up to 5 km (and often up to 10 km with proper link budgets), making it the correct choice for a 2 km link. Single-mode fiber is required for distances beyond 550 m, and 1000BASE-LX is the Gigabit Ethernet standard designed for such single-mode runs.

Answer

1000BASE-T

Answer

1000BASE-SX

Answer

10GBASE-SR

Question 8

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 9

A network administrator is configuring a new switch in a production environment. The switch must be managed remotely. Which of the following should be configured on the switch's management interface?

Accepted Answer

Default gateway. The default gateway is required for remote management because the management interface (often a virtual interface like VLAN 1 or a dedicated management VLAN) needs a route to reach devices on different subnets. Without a default gateway, the switch can only be accessed from hosts within the same subnet, making remote management impossible across routed networks.

Answer

Spanning tree priority

Answer

VLAN 1 membership

Answer

Port security

Question 10

A company is implementing a new wireless network for employees. The network must support seamless roaming between access points. Which protocol should be configured on the wireless controller?

Accepted Answer

802.11r. 802.11r, also known as Fast BSS Transition (FT), enables seamless roaming by allowing a client to authenticate and derive encryption keys with a new access point before or during the reassociation process, reducing the time-sensitive handshake overhead. This is essential for real-time applications like VoIP or video calls where roaming delays must be under 50 ms to avoid perceptible drops.

Answer

802.1X

Answer

802.11n

Answer

802.3af

Question 11

A network engineer configures an 802.1Q trunk between two switches. The trunk is up, but VLAN 10 traffic is not passing. The engineer checks and confirms that VLAN 10 exists on both switches. The show interfaces trunk command displays 'allowed VLANs: none'. What is the most likely cause?

Accepted Answer

The allowed VLAN list is empty. The 'show interfaces trunk' output showing 'allowed VLANs: none' explicitly indicates that the allowed VLAN list on the trunk has been manually cleared or set to none, which blocks all VLAN traffic including VLAN 10. Even though VLAN 10 exists on both switches, the trunk port's VLAN filter prevents any frames from being forwarded. This is the most direct cause of the issue.

Answer

The trunk encapsulation is not set to dot1q

Answer

The native VLAN mismatch

Answer

VLAN 10 is not created on one of the switches

Question 12

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 13

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 14

A network engineer needs to connect two switches located 400 meters apart. The cable run includes high electromagnetic interference from nearby machinery. The engineer decides to use fiber optic cabling. Which transceiver type and fiber combination should be used to ensure the link reaches 400 meters while remaining cost-effective?

Accepted Answer

Multimode fiber with 1000BASE-SX transceivers. 1000BASE-SX transceivers over multimode fiber (typically OM2 or OM3) can reliably reach 400 meters at 1 Gbps, and this combination is cost-effective for short-to-medium distances. Multimode fiber uses a larger core that is cheaper to terminate and pair with lower-cost VCSEL-based SX optics, making it ideal for runs under 550 meters in environments with high EMI.

Answer

Single-mode fiber with 1000BASE-LX transceivers

Answer

Multimode fiber with 10GBASE-SR transceivers

Answer

Single-mode fiber with 1000BASE-EX transceivers

Question 15

A network engineer needs to install 15 wireless access points that each require 25W of power. The available switch provides PoE+ (802.3at) with a total power budget of 740W. The engineer also needs to connect 10 IP cameras that each require 12W. Which of the following should the engineer verify before proceeding with the installation?

Accepted Answer

The total power consumption of all devices does not exceed the switch's power budget.. The total power required is 15 APs × 25W + 10 cameras × 12W = 375W + 120W = 495W, which is well below the switch's 740W PoE+ budget. However, the engineer must verify that the cumulative power draw does not exceed the budget, as exceeding it would cause some ports to be denied power or shut down. This is the fundamental prerequisite for any PoE deployment.

Answer

The switch supports LLDP-MED for power negotiation.

Answer

All PoE devices are from the same manufacturer.

Answer

The cable length does not exceed 150 meters.