CCNA Network Implementation Questions — Page 2 of 2

MCQhard

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?

A.802.11ac (Wi-Fi 5)

B.802.11ax (Wi-Fi 6)

C.802.11n (Wi-Fi 4)

D.802.11g (Wi-Fi 3)

AnswerB

802.11ax (Wi-Fi 6) is the optimal choice for a large warehouse due to its advanced features like Orthogonal Frequency-Division Multiple Access (OFDMA) and enhanced Multi-User Multiple-Input Multiple-Output (MU-MIMO). OFDMA allows the access point to divide a channel into smaller sub-channels, efficiently serving multiple clients simultaneously with varying bandwidth needs, which is crucial for high-density environments with many IoT devices. Furthermore, its support for both 2.4 GHz and 5 GHz bands provides a balance of range, penetration, and high throughput, effectively mitigating interference and ensuring robust coverage across a vast area.

Why this answer

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.

Exam trap

The trap here is that candidates often choose 802.11ac (Wi-Fi 5) because it is widely known for high throughput, but they overlook that 802.11ax's OFDMA and TWT are specifically designed for high-density IoT and interference-heavy environments, not just raw speed.

Why the other options are wrong

802.11ac operates only in the 5 GHz band and lacks OFDMA and BSS Coloring, making it less effective in dense, interference-heavy environments like a warehouse with metal racks and machinery.

802.11n operates in the 2.4 GHz and 5 GHz bands but lacks OFDMA and BSS Coloring, which are critical for handling high-density IoT sensors and mitigating interference in challenging RF environments like a warehouse with metal racks and heavy machinery.

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MCQmedium

A network administrator needs to connect two switches to allow multiple VLANs to traverse the link. Which protocol should be used to tag frames with VLAN information?

A.STP (Spanning Tree Protocol)

B.802.1Q

C.VTP (VLAN Trunking Protocol)

D.LACP (Link Aggregation Control Protocol)

AnswerB

IEEE 802.1Q is the industry standard for VLAN tagging, which is essential for allowing multiple Virtual Local Area Networks (VLANs) to share a single physical link between network devices like switches. It inserts a 4-byte tag into the Ethernet frame header, containing a 12-bit VLAN ID (VID) that identifies the specific VLAN the frame belongs to. This tagging mechanism ensures that frames from different VLANs remain logically separate while traversing a shared trunk port, enabling efficient network segmentation and traffic isolation.

Why this answer

802.1Q is the IEEE standard for VLAN tagging, which inserts a 4-byte tag into the Ethernet frame header to identify the VLAN membership of the frame. This allows multiple VLANs to traverse a single trunk link between switches, enabling inter-switch VLAN communication without requiring separate physical links per VLAN.

Exam trap

The trap here is that candidates often confuse VTP (a management protocol) with the actual tagging protocol, assuming VTP handles frame tagging because of the word 'trunking' in its name.

Why the other options are wrong

STP prevents loops in a network but does not tag frames with VLAN information; it operates at Layer 2 to block redundant paths, not to identify VLAN membership.

VTP is used to synchronize VLAN information across switches, not to tag frames with VLAN information. The protocol for tagging frames is 802.1Q.

LACP is used for link aggregation (combining multiple physical links into one logical link) to increase bandwidth and provide redundancy, not for tagging frames with VLAN information.

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MCQmedium

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?

A.Cat6a twisted-pair copper

B.Multimode fiber optic

C.Single-mode fiber optic

D.Cat5e twisted-pair copper

AnswerB

Multimode fiber optic cable, particularly when utilizing 1000BASE-SX transceivers, is an excellent choice for connecting switches 150 meters apart. This standard reliably supports Gigabit Ethernet (1 Gbps) over distances up to 550 meters using OM4 fiber, or 220-300 meters with OM3, comfortably exceeding the 150-meter requirement. It offers a significantly more cost-effective solution than single-mode fiber for intermediate distances like this, making it the most practical and efficient option.

Why this answer

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.

Exam trap

CompTIA often tests the 100-meter distance limit for twisted-pair copper (Cat5e/Cat6a) at 1 Gbps, and candidates mistakenly assume Cat6a can exceed this due to its higher rating, but the standard still caps it at 100 meters for 1 Gbps.

Why the other options are wrong

Cat6a twisted-pair copper is limited to 100 meters for 10GBASE-T and 1GBASE-T, so it cannot reach 150 meters. The question requires a link of 150 meters, making Cat6a unsuitable.

Single-mode fiber optic is more expensive than multimode fiber and is typically used for longer distances (several kilometers), making it overkill and over budget for a 150-meter link.

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MCQhard

A network engineer is deploying a wireless network using 802.11ac. To allow clients to roam between access points without re-authenticating to the authentication server, which IEEE standard should be implemented?

A.802.1X

B.802.11r

C.802.11i

D.802.11e

AnswerB

IEEE 802.11r, also known as Fast BSS Transition, is the standard specifically designed to enable fast and secure roaming for wireless clients. It minimizes the time required for a client to reassociate from one access point (AP) to another within the same extended service set (ESS) by pre-authenticating with target APs. This significantly reduces latency during handoffs, which is crucial for delay-sensitive applications like Voice over IP (VoIP) or streaming video.

Why this answer

802.11r, also known as Fast BSS Transition (FT), enables clients to roam between access points using a cached Pairwise Master Key (PMK) without requiring a full 802.1X/EAP re-authentication with the RADIUS server. This reduces roaming latency to under 50 ms, which is critical for voice and video applications.

Exam trap

The N10-009 exam often tests the distinction between 802.1X (authentication framework) and 802.11r (fast roaming), leading candidates to mistakenly choose 802.1X because they associate it with 'authentication' without realizing the question specifically asks about avoiding re-authentication during roaming.

Why the other options are wrong

802.1X is an authentication framework used for port-based network access control, not a roaming standard. It requires re-authentication when roaming between access points unless combined with a fast roaming protocol like 802.11r.

802.11i (WPA2) provides security (encryption and authentication) but does not handle fast roaming without re-authentication to the authentication server. The question specifically asks for a standard that allows clients to roam without re-authenticating, which is addressed by 802.11r (Fast Roaming).

802.11e defines QoS enhancements for wireless networks, not fast roaming or authentication caching. The question asks for a standard that allows clients to roam without re-authenticating, which is addressed by 802.11r, not 802.11e.

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MCQmedium

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?

A.Single-mode fiber with 1000BASE-LX transceivers

B.Multimode fiber with 1000BASE-SX transceivers

C.Multimode fiber with 10GBASE-SR transceivers

D.Single-mode fiber with 1000BASE-EX transceivers

AnswerB

1000BASE-SX is a Gigabit Ethernet standard specifically designed for short-wavelength (850 nm) transmission over multimode fiber. It reliably supports distances up to 550 meters when using OM3 or OM4 fiber, making it an ideal and highly suitable choice for a 400-meter link. This option provides the necessary 1Gbps bandwidth at the most cost-effective price point for the specified distance, avoiding unnecessary expenses associated with longer-reach or higher-speed solutions.

Why this answer

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.

Exam trap

The N10-009 exam often tests the misconception that single-mode fiber is always superior or necessary for any distance over 100 meters, but the trap here is ignoring the cost-effectiveness requirement and assuming LX is the only option for 400 meters, when SX over multimode is both sufficient and cheaper.

Why the other options are wrong

Single-mode fiber with 1000BASE-LX can reach 400 meters, but multimode fiber with 1000BASE-SX is more cost-effective for this distance and is designed for shorter runs with high EMI. Single-mode fiber and transceivers are more expensive, making option A less cost-effective.

10GBASE-SR transceivers are designed for 10 Gbps speeds, which is overkill for a 400-meter link and more expensive than 1000BASE-SX. Additionally, multimode fiber with 10GBASE-SR typically supports distances up to 300 meters (OM3) or 400 meters (OM4) at 10 Gbps, but the question asks for a cost-effective solution, and 10GBASE-SR is not cost-effective for 1 Gbps needs.

1000BASE-EX transceivers are designed for single-mode fiber and support distances up to 40 km, which is overkill and more expensive for a 400-meter link. Multimode fiber with 1000BASE-SX is more cost-effective for this distance.

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MCQmedium

A network engineer is designing a subnet for a department that requires exactly 50 usable host addresses. Which subnet mask provides the minimum number of usable host addresses while still accommodating the requirement?

A./26

B./27

C./28

D./25

AnswerA

A /26 CIDR mask allocates 26 bits for the network portion, leaving 6 bits for host addresses. This configuration provides 2^6 = 64 total IP addresses. After reserving one for the network address and one for the broadcast address, 62 usable host addresses remain, which is the smallest subnet size capable of accommodating exactly 50 required hosts without significant waste.

Why this answer

A /26 subnet mask (255.255.255.192) provides 2^(32-26) = 64 total addresses, of which 62 are usable (subtracting network and broadcast addresses). This is the smallest subnet that meets the requirement of exactly 50 usable hosts, as /27 yields only 30 usable addresses and /28 yields only 14, while /25 provides 126 usable addresses, which is more than necessary.

Exam trap

CompTIA often tests the confusion between total addresses and usable addresses, where candidates mistakenly think a /27 (32 total addresses) can support 50 hosts, or they forget to subtract the network and broadcast addresses from the total.

Why the other options are wrong

A /27 subnet provides 2^(32-27)-2 = 30 usable host addresses, which is insufficient for the requirement of 50 usable hosts.

A /28 subnet provides only 14 usable host addresses (2^(32-28)-2 = 14), which is insufficient for the required 50 usable hosts.

A /25 subnet provides 126 usable host addresses, which far exceeds the requirement of 50. The question asks for the minimum number of usable addresses while still accommodating the requirement, so /26 (62 usable) is the correct choice, not /25.

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MCQmedium

A company has just installed a new fiber optic connection between two buildings 2 km apart. The connection is using multimode fiber. However, the signal is too weak at the receiving end. What is the most likely cause?

A.Attenuation due to distance

B.Electromagnetic interference

C.Incorrect termination

D.Crosstalk

AnswerA

Multimode fiber, commonly used for shorter distances within buildings, experiences significant signal loss, known as attenuation, over extended runs. Its larger core allows for multiple light paths, leading to modal dispersion which limits effective transmission distance, especially at higher data rates. A 2 km link far exceeds the typical maximum reach for multimode fiber, which is often less than 550 meters for 10 Gigabit Ethernet, resulting in substantial signal degradation. This distance limitation directly causes the observed signal weakening.

Why this answer

Multimode fiber (MMF) is designed for shorter distances, typically up to 550 meters for 10 Gbps (OM3/OM4) and up to 2 km only for lower speeds like 100 Mbps or 1 Gbps using older OM1/OM2 fiber. At 2 km, the signal attenuation exceeds the power budget of the MMF link, causing a weak signal at the receiver. Single-mode fiber (SMF) would be required for reliable transmission over this distance.

Exam trap

CompTIA often tests the misconception that fiber is immune to all distance limitations, but the trap here is that multimode fiber has strict distance limits due to modal dispersion and higher attenuation, unlike single-mode fiber which can span 2 km easily.

Why the other options are wrong

Incorrect termination can cause signal loss, but the question states the fiber is multimode and the distance is 2 km. Multimode fiber is typically limited to about 550 meters at 10 Gbps; the primary issue is attenuation due to exceeding the distance limit, not termination.

Crosstalk occurs when signals from adjacent cables interfere with each other, typically in copper cabling (e.g., UTP). Fiber optic cables use light, not electricity, so crosstalk is not a concern, especially over a 2 km multimode link where distance-related attenuation is the primary issue.

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MCQhard

A network engineer has configured an IPsec site-to-site VPN between two offices. The tunnel is established and shows as active. However, users at the branch office (10.0.1.0/24) cannot reach servers at the main office (192.168.1.0/24). Both routers have the correct VPN policies and firewall rules permitting IPsec traffic. What should the engineer check next?

A.A) That the DNS server addresses are correctly configured

B.B) That the routing tables on both routers include routes to the remote subnet

C.C) That the MTU size is set to 1500 on both ends

D.D) That the SSID is correctly configured on the access points

AnswerB

Routers use their routing tables to determine the next hop for packets destined for a particular network. For a site-to-site VPN, the router must have a static or dynamic route indicating that traffic for the remote office's private subnet should be encapsulated and sent through the IPSec tunnel interface, rather than out the default internet gateway. Without this specific route, packets will not be directed into the VPN tunnel, preventing communication.

Why this answer

The tunnel being active means Phase 1 and Phase 2 of IPsec are established, but traffic still cannot flow because the routers lack routes to the remote subnets. Without a route for 10.0.1.0/24 on the main office router (or 192.168.1.0/24 on the branch router), packets will be dropped or sent out the wrong interface, even though the VPN policy and firewall rules are correct. The engineer must verify that static routes or a dynamic routing protocol (e.g., OSPF over the tunnel) are in place to direct traffic into the IPsec tunnel interface.

Exam trap

The N10-009 exam often tests the misconception that a 'green light' tunnel status guarantees traffic flow, but candidates forget that routing is a separate layer that must explicitly direct traffic into the tunnel interface.

Why the other options are wrong

The tunnel is active and IPsec traffic is permitted, so DNS is not the issue. The problem is that the branch office cannot reach the main office subnet, which indicates a routing problem, not DNS resolution.

The tunnel is active, indicating IPsec is working; MTU issues typically cause fragmentation or packet loss, not complete unreachability between subnets.

The SSID is a wireless network identifier for Wi-Fi, which is unrelated to IPsec site-to-site VPN connectivity between branch and main office networks.

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MCQmedium

A network administrator is configuring a new switch for management access via SSH. Which step must be performed FIRST?

A.Generate RSA key pair.

B.Configure a VTY password.

C.Enable SSH version 2.

D.Configure an IP address on the management VLAN.

AnswerD

Configuring an IP address on the management VLAN's Switch Virtual Interface (SVI) is the absolute foundational step for remote management via SSH. Without a unique IP address, the switch is not discoverable or reachable over the network at Layer 3, preventing any SSH client from initiating a connection. This IP address provides the essential network identity and connectivity required before any higher-level security or access protocols can function for remote administration.

Why this answer

Before SSH can function, the switch must have an IP address assigned to the management VLAN (typically VLAN 1 or a dedicated management VLAN) so that the switch is reachable over the network. Without this IP configuration, the switch cannot establish the TCP/IP connectivity required for SSH sessions, making it the foundational step that must be performed first.

Exam trap

The trap here is that candidates often assume SSH configuration begins with key generation or version selection, forgetting that the switch must first have an IP address on the management VLAN to be reachable for any remote management protocol.

Why the other options are wrong

Configuring a VTY password is necessary for remote access, but the switch must first have an IP address on the management VLAN to be reachable over the network. Without IP connectivity, SSH cannot be established.

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MCQhard

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?

A.10GBASE-SR with multimode fiber

B.1000BASE-LX with single-mode fiber

C.10GBASE-LR with single-mode fiber

D.1000BASE-SX with multimode fiber

AnswerC

10GBASE-LR is the optimal choice because it provides a high-speed 10 Gigabit Ethernet connection over single-mode fiber. Its design allows for reaches up to 10 kilometers, far exceeding the required 450 meters while maintaining full data rate. Single-mode fiber is ideal for such distances, ensuring signal integrity and minimal attenuation, making it perfectly suited for connecting switches 450 meters apart.

Why this answer

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.

Exam trap

The trap here is that candidates assume 10GBASE-SR is sufficient for 450 meters, but the maximum distance for 10GBASE-SR over OM3 MMF is 300 meters, and over OM4 it is 400 meters—both fall short of 450 meters, making 10GBASE-LR the correct choice for the highest data rate.

Why the other options are wrong

10GBASE-SR over multimode fiber is limited to distances around 300-400 meters (depending on OM3/OM4), so it cannot reliably support 450 meters. Single-mode fiber with 10GBASE-LR is required for that distance at 10 Gbps.

1000BASE-LX supports only 1 Gbps, while the question asks for the highest data rate over 450 meters. 10GBASE-LR provides 10 Gbps, which is higher.

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Drag & Dropmedium

Drag and drop the steps in the DHCP lease process (DORA) into the correct order.

Drag or tap steps into the slots.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

Why this order

The DHCP lease process follows the DORA sequence: Discover, Offer, Request, Acknowledge. The client initiates by broadcasting a Discover packet. DHCP servers reply with an Offer containing an IP address.

The client then sends a Request to formally accept one offer. Finally, the server sends an Acknowledge to confirm the lease and provide additional configuration parameters. This order ensures proper negotiation and avoids conflicts.

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MCQmedium

A network engineer is implementing OSPF on a router. All directly connected neighbors are listed with state FULL, but routes from another area are not appearing in the routing table. Which of the following is the most likely cause?

A.The router is not configured with a router ID

B.The router has an ACL blocking inbound OSPF updates

C.The router is configured as an ABR but does not have a virtual-link configured

D.The link-state database is corrupted

AnswerB

An Access Control List (ACL) configured to deny inbound OSPF protocol traffic (IP protocol 89) would specifically prevent the reception of Link-State Advertisements (LSAs) from other areas. While OSPF neighbor adjacencies, which primarily rely on Hello packets, might still form and reach a FULL state within the local area, the router would fail to populate its routing table with inter-area routes (e.g., those advertised via Type 3 LSAs). This scenario perfectly explains why local adjacencies are full but routes to other areas are missing.

Why this answer

An ACL applied to the OSPF process or interface can filter inbound Type 3 LSAs (summary LSAs) from other areas. Even though neighbor adjacencies reach FULL state, the router will not install those inter-area routes into the routing table if the ACL blocks the LSA updates. This explains why directly connected neighbors are fine but routes from another area are missing.

Exam trap

The N10-009 exam often tests the misconception that FULL neighbor state guarantees all routes are learned, when in fact ACLs or distribute-lists can filter LSAs without affecting the neighbor relationship.

Why the other options are wrong

OSPF can dynamically assign a router ID using the highest loopback or physical IP address if none is configured, so missing a router ID would not prevent routes from another area from appearing.

A corrupted link-state database would typically cause OSPF neighbor states to not reach FULL or cause routing loops, not specifically prevent routes from another area from appearing while neighbors are FULL.

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MCQhard

A network administrator is configuring dynamic routing between two routers in the same organization. The routers must support VLSM, converge quickly, and use a metric that is based on bandwidth and delay. Which routing protocol should be configured?

A.RIP

B.OSPF

C.EIGRP

D.BGP

AnswerC

EIGRP (Enhanced Interior Gateway Routing Protocol) is a sophisticated Cisco proprietary distance-vector routing protocol, often described as a hybrid, known for its rapid convergence and efficient use of network resources. It fully supports Variable Length Subnet Masks (VLSM) and calculates its composite metric using bandwidth, delay, reliability, and load, with bandwidth and delay being the default components. This allows EIGRP to make intelligent routing decisions based on actual link characteristics, making it highly suitable for internal routing within a single autonomous system.

Why this answer

C is correct because EIGRP is a Cisco-proprietary hybrid routing protocol that supports Variable-Length Subnet Masking (VLSM), converges rapidly using the Diffusing Update Algorithm (DUAL), and uses a composite metric that by default includes bandwidth and delay. This makes it ideal for the scenario where both VLSM support and fast convergence are required with a metric based on bandwidth and delay.

Exam trap

The trap here is that candidates often choose OSPF because it is a widely used link-state protocol that supports VLSM and converges quickly, but they overlook the specific requirement for a metric based on both bandwidth and delay, which is unique to EIGRP's default composite metric.

Why the other options are wrong

RIP uses hop count as its metric, not bandwidth and delay, and converges slowly due to its periodic updates and hold-down timers. It also does not support VLSM in RIPv1, though RIPv2 does, but it still lacks the required metric and fast convergence.

OSPF uses cost as its metric, which is typically based on bandwidth but not delay. The question requires a metric based on both bandwidth and delay, which is a feature of EIGRP, not OSPF.

BGP uses a path-vector algorithm with complex attributes like AS-path, not bandwidth and delay, and converges slowly, making it unsuitable for this internal routing scenario requiring fast convergence and VLSM support.

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MCQmedium

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?

A.802.11ac (Wi-Fi 5)

B.802.11ax (Wi-Fi 6)

C.802.11n (Wi-Fi 4)

D.802.11b (Wi-Fi 1)

AnswerA

Correct. 802.11ac provides high throughput and supports many clients with MU-MIMO, at a lower cost than 802.11ax, making it ideal for budget-constrained dense deployments.

Why this answer

802.11ac (Wi-Fi 5) is the best choice for this scenario because it offers high throughput (up to 1.3 Gbps in the 5 GHz band) and supports MU-MIMO (downlink) for handling multiple clients simultaneously, all at a lower cost than 802.11ax (Wi-Fi 6). Since the organization is budget-constrained, 802.11ac provides a good balance of performance and affordability for a dense open office environment.

Exam trap

Candidates may assume that newer is always better and choose 802.11ax, but the budget constraint makes 802.11ac the more practical and cost-effective option for high throughput and many simultaneous clients.

Why the other options are wrong

802.11n (Wi-Fi 4) is outdated and offers lower throughput (up to 600 Mbps) and less efficient handling of many simultaneous clients compared to 802.11ax, which is designed for high-density environments.

802.11b (Wi-Fi 1) offers a maximum data rate of only 11 Mbps and supports very few simultaneous clients, making it unsuitable for high throughput and dense client environments.

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MCQmedium

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

A.802.3af

B.802.11ac

C.802.1X

D.802.3ab

AnswerA

802.3af is the IEEE standard specifically designed for Power over Ethernet (PoE), enabling network devices like IP phones and wireless access points to receive electrical power and data over a single Ethernet cable. This standard provides up to 15.4 watts of DC power to powered devices (PDs) at the port, significantly simplifying infrastructure by eliminating the need for separate power outlets and cabling near the endpoint devices.

Why this answer

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.

Exam trap

The trap here is confusing the 802.3 family of wired Ethernet standards (which includes PoE) with the 802.11 family of wireless standards (like 802.11ac), leading candidates to mistakenly select a Wi-Fi standard for a power-over-cable requirement.

Why the other options are wrong

802.11ac is a wireless networking standard for Wi-Fi, not a Power over Ethernet (PoE) standard. It does not define power delivery over Ethernet cables.

802.1X is an authentication protocol for network access control, not a standard for powering devices over Ethernet. The question asks for a standard that provides power over Ethernet, which is addressed by IEEE 802.3af (PoE).

802.3ab defines Gigabit Ethernet over copper (1000BASE-T), not Power over Ethernet (PoE). It does not provide power delivery.

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Drag & Dropmedium

Drag and drop the steps for the TCP three-way handshake into the correct order.

Drag or tap steps into the slots.

Steps

Order

1Step 1

2Step 2

3Step 3

4Step 4

Why this order

The TCP three-way handshake is a fundamental process for establishing a connection. It begins with the client sending a SYN packet to the server. The server responds with a SYN-ACK packet, acknowledging the client's SYN and sending its own SYN.

Finally, the client sends an ACK packet to acknowledge the server's SYN, completing the handshake. This sequence ensures both sides agree on initial sequence numbers and are ready to communicate.

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MCQmedium

A network engineer is configuring a new wireless deployment in a warehouse with hundreds of metal racks. Users report intermittent connectivity and slow throughput when walking between aisles. The engineer decides to perform a site survey and adjust the wireless design. Which of the following should the engineer implement to improve coverage and reduce interference in this environment?

A.Configure all access points to use the same channel to simplify roaming.

B.Increase the transmit power on all access points to maximum to penetrate the metal racks.

C.Enable 802.11ax on all access points and disable 2.4 GHz to reduce interference.

D.Deploy directional antennas and perform a site survey to adjust AP placement and channel assignments.

AnswerD

Directional antennas focus signal down aisles, overcoming metal rack obstructions, while a site survey identifies dead zones and interference. Adjusting AP placement and channel assignments reduces co-channel interference. This combination directly addresses coverage and interference in a warehouse environment, making it the correct approach.

Why this answer

In a warehouse with metal racks, signal reflection, absorption, and interference are major challenges. Directional antennas can focus coverage down aisles, and a thorough site survey ensures proper AP placement and channel reuse. This combination minimizes dead zones and co-channel interference, directly improving coverage and throughput for users moving between aisles.

Exam trap

The trap here is assuming that increasing transmit power or using the same channel will solve coverage issues, when in fact they often worsen interference and do not address physical obstructions.

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MCQmedium

A network engineer is configuring a trunk link between two switches to carry VLANs 10, 20, and 30. On Switch A, the port is configured with 'switchport mode trunk' and 'switchport nonegotiate'. On Switch B, the port is left at the default configuration. Which additional configuration is required on Switch B?

A.Set the native VLAN to 1.

B.Enable DTP on Switch B.

C.Manually set the port to trunk mode.

D.Configure the allowed VLAN list.

AnswerC

Since Switch A is set to 'nonegotiate', Switch B must be manually configured as a trunk port (e.g., 'switchport mode trunk') to establish the trunk link.

Why this answer

Switch B is left at default configuration, which on most Cisco switches means the port is in dynamic desirable or dynamic auto mode, relying on DTP to negotiate trunking. Since Switch A has 'switchport nonegotiate' configured, it will not send DTP frames, so Switch B will never receive a negotiation trigger and will remain in access mode. Therefore, the port on Switch B must be manually set to trunk mode with 'switchport mode trunk' to establish the trunk link.

Exam trap

CompTIA often tests the misconception that DTP is always required or that 'switchport nonegotiate' only affects DTP on the local switch, when in fact it prevents the remote switch from ever learning that trunking is desired, forcing a manual configuration on the remote end.

Why the other options are wrong

Switch B's port is at default configuration, which means DTP is enabled and the port is in dynamic desirable mode. Since Switch A has 'switchport nonegotiate', DTP frames are not sent, so Switch B cannot automatically negotiate trunking. Setting the native VLAN to 1 is already the default and does not enable trunking.

Switch B is left at default configuration, which means DTP is enabled by default. However, Switch A has 'switchport nonegotiate', so DTP frames are not sent. Enabling DTP on Switch B would not help because Switch A will not respond to DTP; the port must be manually set to trunk mode.

The allowed VLAN list is already implicitly defined by the requirement to carry VLANs 10, 20, and 30; DTP negotiation is not needed because Switch A uses nonegotiate, and the issue is that Switch B remains in default dynamic auto mode, which will not form a trunk without manual configuration.

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MCQmedium

A network engineer is configuring a Link Aggregation Group (LAG) between two switches. Switch A is set to LACP active mode. Which mode should be configured on Switch B to form the LAG?

A.Passive

B.On

C.Static

D.Auto

AnswerA

LACP passive mode enables an interface to listen for LACP Data Units (LACPDUs) from a peer and then respond to form a Link Aggregation Group (LAG). While it does not actively initiate LACP negotiation, it will successfully establish a bundled link with an LACP active port, which is constantly sending LACPDUs to discover and form a LAG. This complementary behavior ensures the two switches can dynamically agree on the aggregated links.

Why this answer

LACP active mode initiates negotiation by sending LACP packets, while passive mode responds to those packets without initiating. Since Switch A is set to active, Switch B must be in passive mode to successfully form a Link Aggregation Group (LAG). This combination allows the two switches to exchange LACP frames and agree on the aggregation parameters.

Exam trap

The N10-009 exam often tests the distinction between LACP modes (active/passive) and PAgP modes (desirable/auto), leading candidates to mistakenly choose 'Auto' (a PAgP mode) for LACP questions.

Why the other options are wrong

LACP 'On' mode (also called manual or static) does not use LACP negotiation; it forces the link into a LAG without exchanging LACP frames. Since Switch A is in LACP active mode, Switch B must be in LACP passive mode to successfully negotiate the LAG via LACP.

In this question, LACP is explicitly used (Switch A is in active mode), so the peer must use LACP passive mode. 'Static' is not a valid LACP mode; it refers to a manual LAG without LACP, which would not interoperate with LACP active.

In LACP, 'Auto' is a Cisco proprietary mode that initiates negotiation only if the remote side is set to 'Desirable'. Since Switch A is in LACP 'Active' mode, Switch B must be in LACP 'Passive' mode to form a LAG; 'Auto' is not a valid LACP mode.

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MCQeasy

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?

A.Default gateway

B.Spanning tree priority

C.VLAN 1 membership

D.Port security

AnswerA

The default gateway is absolutely essential for remote management because it provides the switch's management interface with a route to reach devices outside its directly connected local subnet. Without a configured default gateway, the switch can only communicate with other devices within its immediate broadcast domain, making remote administration from a different network segment or the internet impossible. This setting directs all non-local IP traffic to the appropriate router for forwarding.

Why this answer

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.

Exam trap

The trap here is that candidates often think VLAN 1 membership (Option C) is sufficient for remote management, forgetting that the switch needs a default gateway to route management traffic beyond its local subnet.

Why the other options are wrong

Spanning tree priority is a configuration for the Spanning Tree Protocol (STP) to influence root bridge election, not for enabling remote management of the switch's management interface.

VLAN 1 membership is the default for all switch ports and does not enable remote management; remote management requires an IP address and default gateway on the management interface.

Port security is a feature that restricts which MAC addresses can communicate through a switch port, but it is not required for remote management of the switch's management interface.

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MCQmedium

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?

A.PVC-jacketed cable

B.Riser-rated cable

C.Plenum-rated cable

D.Low Smoke Zero Halogen (LSZH) cable

AnswerC

Plenum-rated cables are specifically engineered with advanced fire-retardant materials, such as fluorinated polymers like FEP or PVDF, which exhibit extremely low smoke production and flame spread characteristics when exposed to fire. This critical design ensures that in the event of a fire, the cable will not contribute significantly to the rapid distribution of smoke or flames through a building's air-handling systems. Adherence to stringent standards like NFPA 90A and UL 910 is mandatory for these cables to be installed in plenum spaces, protecting occupants and preventing widespread damage.

Why this answer

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.

Exam trap

The trap here is that candidates often confuse 'plenum-rated' with 'riser-rated' or 'LSZH', assuming any low-smoke cable suffices, but the exam specifically tests that only CMP meets the fire and smoke spread requirements for plenum spaces as defined by the NEC.

Why the other options are wrong

PVC-jacketed cable is not allowed in plenum spaces because it produces toxic smoke and supports flame propagation, violating building codes that require low-smoke, fire-resistant materials.

Riser-rated cable is designed for vertical runs between floors, not for plenum spaces where air circulates. Building codes require plenum-rated cable in plenums due to its low smoke and flame spread properties.

LSZH cable is designed to emit low smoke and no halogens when burned, but it is not specifically rated for plenum spaces; plenum-rated cable is required by building codes for air-handling spaces due to its fire-resistant and low-smoke properties.

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MCQmedium

A network administrator is configuring Quality of Service (QoS) on a router to prioritize voice traffic. Which of the following fields should be used to mark packets for classification and prioritization?

A.Source IP address

B.DSCP

C.Source port number

D.MAC address

AnswerB

DSCP (Differentiated Services Code Point) is a 6-bit field within the Type of Service (ToS) byte of the IPv4 header, or the Traffic Class field in IPv6. Routers use DSCP values to classify and mark packets, assigning them to specific per-hop behaviors (PHBs) such as expedited forwarding (EF) for voice or assured forwarding (AF) for critical data. This marking enables consistent end-to-end QoS prioritization across diverse network devices, ensuring that high-priority traffic receives preferential treatment regardless of its origin or destination.

Why this answer

DSCP (Differentiated Services Code Point) is the correct field because it is a 6-bit value in the IP header used to mark packets for QoS classification and prioritization, as defined in RFC 2474. Voice traffic typically uses DSCP EF (Expedited Forwarding, value 46) to ensure low latency and jitter, making it the standard choice for QoS marking on routers.

Exam trap

The trap here is that candidates confuse classification (using source IP, port, or MAC to identify traffic) with marking (setting a QoS field like DSCP or CoS), leading them to choose a valid classification method instead of the actual marking field required by the question.

Why the other options are wrong

QoS marking for classification and prioritization uses Layer 3 fields like DSCP or IP Precedence, not the source IP address. The source IP identifies the sender but does not carry QoS priority information.

Source port number is a transport-layer field used for identifying applications, but QoS marking for voice traffic is typically done at Layer 3 using DSCP (e.g., EF for voice), not by source port.

MAC addresses operate at Layer 2 and are not used for QoS marking in IP networks; QoS classification and prioritization rely on Layer 3 fields like DSCP or IP precedence.

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MCQeasy

A network technician needs to connect two switches to support multiple VLANs between them. The technician wants to use a single link to carry traffic for all VLANs. Which protocol should be used to tag frames with VLAN information?

A.802.1Q

B.802.1X

C.802.11

D.802.3

AnswerA

IEEE 802.1Q is the industry standard for Virtual Local Area Network (VLAN) tagging, essential for enabling multiple VLANs to traverse a single physical link, known as a trunk port, between switches. It inserts a 4-byte tag into the Ethernet frame header, identifying the VLAN to which the frame belongs. This allows switches to properly forward traffic to the correct VLAN segment on the receiving end, effectively segmenting network traffic while utilizing shared physical infrastructure.

Why this answer

802.1Q is the IEEE standard for VLAN tagging, which inserts a 4-byte tag into the Ethernet frame header to identify the VLAN membership of the frame. This allows a single trunk link between two switches to carry traffic for multiple VLANs by tagging each frame with its corresponding VLAN ID (1-4094).

Exam trap

The trap here is that candidates often confuse 802.1Q (VLAN tagging) with 802.1X (port authentication) because of the similar numbering, or they assume 802.3 handles VLANs since it is the base Ethernet standard.

Why the other options are wrong

802.1X is a port-based network access control protocol used for authentication, not for tagging frames with VLAN information. It does not provide VLAN tagging capabilities.

802.11 is a wireless networking standard (Wi-Fi), not a protocol for tagging VLAN frames on Ethernet links between switches.

802.3 is an Ethernet standard that defines physical and data link layer specifications, but it does not include VLAN tagging. VLAN tagging is accomplished by 802.1Q, which inserts a VLAN tag into the Ethernet frame.

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