N10-009 Network Implementation Practice Test 4 — 15 Questions

Question 1

A network administrator is creating a new VLAN that will contain 20 devices. The administrator wants to use the most efficient subnet that provides enough usable IP addresses while minimizing waste. Which of the following subnet masks should be used?

Accepted Answer

255.255.255.224 (/27). A /27 subnet mask (255.255.255.224) provides 32 total addresses, of which 30 are usable (2^5 - 2 = 30). This is the most efficient choice for 20 devices because it offers exactly enough usable IPs with minimal waste (only 10 unused addresses), whereas a /28 would provide only 14 usable addresses (insufficient) and a /29 would provide only 6 usable addresses (also insufficient).

Answer

255.255.255.240 (/28)

Answer

255.255.255.248 (/29)

Answer

255.255.255.192 (/26)

Question 2

A network administrator is installing cable in a plenum space (an area used for air circulation, such as above a drop ceiling). Which cable type is required by most building codes for such an installation?

Accepted Answer

Plenum-rated cable. Plenum-rated cable is required by most building codes (e.g., NFPA 70, National Electrical Code) for installation in plenum spaces because it is constructed with fire-retardant materials, such as FEP or PFA, that produce minimal smoke and are self-extinguishing. This prevents toxic fumes and flames from spreading through air-handling areas, ensuring safety in case of a fire. Standard PVC-jacketed cable would release hazardous smoke and support flame propagation, making it illegal in plenum spaces.

Answer

PVC-jacketed cable

Answer

Riser-rated cable

Answer

Low Smoke Zero Halogen (LSZH) cable

Question 3

A network engineer needs to connect two switches that are located 450 meters apart. Which combination of fiber optic transceiver and cable type would support the highest data rate over this distance?

Accepted Answer

10GBASE-LR with single-mode fiber. 10GBASE-LR (Long Reach) supports 10 Gbps over single-mode fiber (SMF) up to 10 km, easily covering the 450-meter distance. Single-mode fiber has a smaller core (9 µm) that minimizes modal dispersion, enabling higher data rates over longer distances compared to multimode fiber. This combination provides the highest data rate (10 Gbps) among the options for the given distance.

Answer

10GBASE-SR with multimode fiber

Answer

1000BASE-LX with single-mode fiber

Answer

1000BASE-SX with multimode fiber

Question 4

A network engineer needs to deploy a new wireless network in a large office with many cubicles. The goal is to provide high throughput and support multiple simultaneous users. Which IEEE standard should be implemented?

Accepted Answer

802.11ac. 802.11ac (Wi-Fi 5) operates exclusively in the 5 GHz band, uses wider 80 MHz or 160 MHz channels, and supports MU-MIMO (Multi-User Multiple Input Multiple Output) to deliver high throughput and efficient handling of multiple simultaneous users in a dense office environment. This makes it the best choice among the options for a modern, high-capacity wireless deployment.

Answer

802.11n

Answer

802.11b

Answer

802.11g

Question 5

A company is connecting two buildings that are 300 meters apart. The link must support 10 Gbps. Which combination of cable and transceiver should be used?

Accepted Answer

Single-mode fiber with 10GBASE-LR. Option C is correct because single-mode fiber (SMF) with 10GBASE-LR supports 10 Gbps over distances up to 10 km, easily covering the 300-meter requirement. 10GBASE-LR uses 1310 nm laser optics over single-mode fiber, providing low signal loss and high bandwidth for long-reach links.

Answer

Cat6a UTP with 10GBASE-T

Answer

Cat5e UTP with 1000BASE-T

Answer

Multimode fiber with 10GBASE-SR

Question 6

A network administrator is configuring a new switch to carry traffic for multiple VLANs on a single link to a router. Which IEEE standard is used for VLAN tagging on Ethernet trunks?

Accepted Answer

802.1Q. 802.1Q is the IEEE standard that defines VLAN tagging on Ethernet trunks, inserting a 4-byte tag into the Ethernet frame to identify VLAN membership. This allows multiple VLANs to traverse a single link between a switch and a router, enabling inter-VLAN routing without separate physical interfaces.

Answer

802.3af

Answer

802.1D

Answer

802.11ac

Question 7

A small office has multiple devices that need internet access but the ISP provides only a single public IPv4 address. Which network address translation (NAT) technique is most appropriate to allow all internal hosts to share that one public address?

Accepted Answer

PAT (Port Address Translation). PAT (Port Address Translation), also known as NAT overload, is the correct choice because it allows multiple internal hosts to share a single public IPv4 address by mapping each unique internal IP:port combination to a different source port on the public address. This is the only NAT technique that provides many-to-one address translation, which is exactly what a small office with more devices than public IPs requires.

Answer

Static NAT

Answer

Dynamic NAT

Answer

IP masquerading

Question 8

A network engineer is implementing VLANs for a company. The finance department's workstations are connected to switch ports configured as access ports in VLAN 20. The finance server is located in a different building and is connected to a second switch. The two switches are interconnected via a trunk link. What must be configured on the trunk link to allow finance workstations to communicate with the finance server?

Accepted Answer

Allow VLAN 20 on the trunk. A trunk link carries traffic for multiple VLANs. By default, all VLANs are allowed on a trunk, but if VLAN 20 is not explicitly permitted, its traffic will be dropped. Configuring 'switchport trunk allowed vlan 20' on both ends ensures that frames tagged with VLAN 20 traverse the trunk, enabling communication between the finance workstations (access ports in VLAN 20) and the finance server.

Answer

Set the native VLAN to 20 on both switches

Answer

Configure the trunk port as an access port in VLAN 20

Answer

Enable VLAN pruning for all VLANs on the trunk

Question 9

A network engineer is designing a wireless network for a large warehouse with many metal racks and heavy machinery that cause significant RF interference. The network must support a high density of IoT sensors and provide reliable connectivity. Which IEEE wireless standard should the engineer implement to best meet these requirements?

Accepted Answer

802.11ax (Wi-Fi 6). 802.11ax (Wi-Fi 6) is the correct choice because it introduces Orthogonal Frequency Division Multiple Access (OFDMA), which subdivides channels into smaller resource units (RUs) to serve multiple IoT sensors simultaneously, improving efficiency in dense, interference-heavy environments. Additionally, Wi-Fi 6 includes BSS Coloring, which reduces co-channel interference by allowing devices to ignore transmissions from overlapping basic service sets, and Target Wake Time (TWT), which schedules IoT sensor transmissions to conserve battery and reduce contention.

Answer

802.11ac (Wi-Fi 5)

Answer

802.11n (Wi-Fi 4)

Answer

802.11g (Wi-Fi 3)

Question 10

A network engineer is designing a new switched network and needs to ensure that broadcast traffic from one department does not reach another department's workstations. The engineer plans to use VLANs. Which of the following must be configured on the switches to isolate broadcast domains as intended?

Accepted Answer

Assign each department's workstations to a unique VLAN and configure their switch ports as access ports in that VLAN.. VLANs segment a switched network into separate broadcast domains at Layer 2. By assigning each department's workstations to a unique VLAN and configuring their switch ports as access ports in that VLAN, broadcast traffic from one VLAN is confined to that VLAN and cannot reach workstations in another VLAN. This achieves the isolation required without additional filtering devices.

Answer

Configure all switch ports as trunk ports and use VLAN 1 for all departments.

Answer

Place all workstations in the same VLAN and use a firewall to filter broadcast traffic between departments.

Answer

Configure each switch port as a trunk and use a different native VLAN for each department.

Question 11

A network engineer is planning to connect two switches that are 150 meters apart. The link must support at least 1 Gbps and the budget is limited. Which cable type should be used?

Accepted Answer

Multimode fiber optic. Multimode fiber optic cable supports 1 Gbps over distances up to 550 meters (OM2) or more, easily covering the 150-meter requirement at a lower cost than single-mode fiber. It is the best choice for this distance and budget because twisted-pair copper (Cat5e/Cat6a) is limited to 100 meters for 1 Gbps, and single-mode fiber is more expensive due to laser-based transceivers.

Answer

Cat6a twisted-pair copper

Answer

Single-mode fiber optic

Answer

Cat5e twisted-pair copper

Question 12

A network administrator is connecting two switches to increase bandwidth and provide redundancy. Which technology should be used to combine multiple physical links into a single logical link?

Accepted Answer

Link Aggregation Control Protocol. Link Aggregation Control Protocol (LACP) is the correct technology because it allows multiple physical Ethernet links to be combined into a single logical link, increasing aggregate bandwidth and providing redundancy. LACP (IEEE 802.3ad) automatically negotiates and manages the bundling of ports between switches, ensuring that traffic is load-balanced across the member links and that the bundle remains operational even if one physical link fails.

Answer

Spanning Tree Protocol

Answer

VLAN Trunking Protocol

Answer

Rapid Spanning Tree Protocol

Question 13

A network engineer is designing an OSPF network for a large enterprise. To reduce the size of routing tables and limit the propagation of external routes, the engineer wants to use a special area that blocks Type 5 LSAs but still allows inter-area routes via a default route. Which type of OSPF area should be configured?

Accepted Answer

Stub area. A stub area blocks Type 5 LSAs (external routes) from entering the area, forcing the area border router (ABR) to inject a default route (0.0.0.0/0) for reaching external destinations. This reduces the routing table size while still allowing inter-area routes (Type 3 LSAs) to propagate, exactly matching the requirement.

Answer

Backbone area 0

Answer

Standard area

Answer

Totally stubby area

Question 14

A network administrator connects two switches with a trunk link that is configured to allow all VLANs. Workstations in VLAN 10 can communicate across the switches, but workstations in VLAN 20 cannot. Both VLANs are configured on the first switch. What is the most likely cause of the issue?

Accepted Answer

VLAN 20 is not created on the second switch.. VLAN 20 is configured on the first switch but not on the second switch. Even though the trunk link allows all VLANs, the second switch must have VLAN 20 created in its VLAN database for traffic to be forwarded. Without the VLAN existing on the second switch, frames tagged for VLAN 20 are dropped at the receiving switch because there is no corresponding VLAN interface or forwarding table entry.

Answer

The native VLAN is mismatched on the two switches.

Answer

The trunk uses ISL instead of 802.1Q.

Answer

The default gateway is missing for VLAN 20.

Question 15

An organization wants to deploy Wi-Fi in a large, open office space. They need high throughput and the ability to support many simultaneous clients, but they are budget-constrained. Which IEEE wireless standard should they choose?

Accepted Answer

802.11ax (Wi-Fi 6). 802.11ax (Wi-Fi 6) is the correct choice because it introduces Orthogonal Frequency Division Multiple Access (OFDMA) and MU-MIMO (both uplink and downlink), which significantly improve throughput and capacity in dense environments. It also operates in both 2.4 GHz and 5 GHz bands, providing backward compatibility and better spectrum utilization, all while maintaining cost-effectiveness for large-scale deployments.

Answer

802.11ac (Wi-Fi 5)

Answer

802.11n (Wi-Fi 4)

Answer

802.11b (Wi-Fi 1)