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Question 901Question →

A network technician needs to connect multiple endpoint devices in a local office environment. The operational requirement dictates that each connected device must reside in its own dedicated collision domain while all devices remain within a single, shared broadcast domain for local communication. Which network component fulfills this primary role?

Show answer & explanation

Answer: Layer 2 switch

Answer

Layer 2 switch
A Layer 2 switch provides microsegmentation, placing every connected port into its own individual collision domain. However, unless VLANs are configured, all switch ports reside within a single broadcast domain, allowing broadcast frames to reach all connected endpoints.

Step-by-Step Solution

1
Identify collision domain capabilities
Each microsegmented port on a Layer 2 switch forms its own distinct collision domain.
Switches buffer frames per port and support full-duplex operation, eliminating collisions between endpoints.
2
Identify broadcast domain capabilities
By default, all ports on an unconfigured Layer 2 switch belong to the same broadcast domain.
Switches flood Layer 2 broadcast frames out all active ports except the receiving port within the same VLAN.

Key Concept

Layer 2 Switch Domain Boundaries
Estimated Time:45s
Question 902Question →

An enterprise network engineer is reviewing the functional boundaries of network components deployed at a branch office. The topology includes Layer 2 access switches, a Layer 3 distribution switch acting as the Inter-VLAN routing gateway, and a perimeter router. Which two functions are performed by Layer 3 switches or routers, but are NOT supported on standard Layer 2 switches? (Choose two.)

Select all that apply

Show answer & explanation

Answer: Forwarding traffic between different IPv4 subnets using IP header destination addresses; Containing broadcast traffic to specific VLANs by acting as default gateways for routed subnets

Answer

The functions performed exclusively by Layer 3 switches or routers are forwarding traffic between different IPv4 subnets based on destination IP addresses and containing broadcast domains by acting as default gateways.
Layer 3 switches and routers operate at Layer 3 of the OSI model, allowing them to inspect destination IP addresses to route packets between distinct subnets and restrict broadcast traffic from crossing subnets. Standard Layer 2 switches only forward frames within a single VLAN based on Layer 2 MAC addresses.

Step-by-Step Solution

1
Analyze the operational capabilities of standard Layer 2 switches
Layer 2 switches make forwarding decisions based on Layer 2 MAC addresses within a single broadcast domain/subnet and separate collision domains per port.
Layer 2 switches lack routing logic and routing tables needed to forward packets across different subnets.
2
Analyze the operational capabilities of Layer 3 switches and routers
Layer 3 switches and routers inspect Layer 3 IP headers to route packets between subnets and define broadcast domain boundaries.
Broadcast frames are not forwarded past Layer 3 boundaries (routers/L3 interfaces), isolating broadcast domains.
3
Compare capabilities and identify unique Layer 3 functions
Inter-subnet routing based on IP destination addresses and broadcast domain isolation are Layer 3 routing functions.
Collision domain isolation is accomplished by both Layer 2 and Layer 3 switches on every port.

Key Concept

Distinguishing Layer 2 switching capabilities (MAC addressing, collision domain segmentation) from Layer 3 routing capabilities (IP addressing, inter-subnet forwarding, broadcast domain segmentation).
Estimated Time:1m 30s
Question 903Question →

A network engineer is optimizing a high-density 5 GHz wireless deployment in a large corporate conference hall. During testing, wireless clients experience significant performance degradation and latency due to co-channel interference (CCI) caused by adjacent access points operating on overlapping RF cells using the same 20 MHz channels. The engineer must reduce CCI while keeping all access points active to handle client capacity. Which action on the Wireless LAN Controller (WLC) directly resolves this issue?

Show answer & explanation

Answer: Decrease the Transmit Power Control (TPC) maximum power threshold on the WLC to shrink the RF cell size of each access point.

Answer

Decrease the Transmit Power Control (TPC) maximum power threshold on the WLC to shrink the RF cell size of each access point.
Decreasing the Transmit Power Control (TPC) maximum power limit forces the Wireless LAN Controller to restrict the output power of individual AP radios. This reduces each AP's RF coverage cell radius, minimizing signal overlap with neighboring APs on the same channel and reducing co-channel interference (CCI) in high-density environments.

Step-by-Step Solution

1
Analyze the primary cause of wireless performance degradation in high-density environments.
Co-channel interference (CCI) occurs when multiple access points using the same frequency channel are located close enough for their RF coverage cells to overlap, forcing clients and APs to wait for the medium to clear.
Wi-Fi uses CSMA/CA, so APs on the same channel share contention domains if they hear each other above the clear channel assessment threshold.
2
Evaluate how Transmit Power Control (TPC) affects RF cell boundaries and co-channel overlap.
Lowering the maximum allowed transmit power via TPC shrinks the physical RF cell boundary of each AP.
Smaller RF cell footprints reduce the coverage overlap between APs operating on identical channels while preserving total network capacity through dense AP placement.
3
Identify why alternative configuration options fail to mitigate CCI.
Channel bonding decreases the total count of non-overlapping channels, FlexConnect affects traffic switching rather than RRM calculations, and lowering basic rates increases cell size and management overhead.
Only TPC power reduction directly curtails the physical reach of the RF signal causing CCI.

Key Concept

Wireless Radio Resource Management (RRM) and Co-Channel Interference (CCI) mitigation in high-density WLAN deployments.
Question 904Question →

An enterprise server administrator is investigating severe packet delay and high CPU scheduling contention affecting virtual machines during peak traffic periods. Inspection reveals that the virtualization environment operates on top of a standard Linux distribution host operating system, requiring the virtual switch to pass frame processing requests through the host OS kernel and physical device drivers. Which architectural migration eliminates host operating system overhead by allowing the hypervisor to directly schedule hardware resources and manage physical network interfaces?

Show answer & explanation

Answer: Deploying a Type 1 bare-metal hypervisor directly on the underlying server hardware.

Answer

Deploying a Type 1 bare-metal hypervisor directly on the underlying server hardware resolves host operating system overhead.
Migrating to a Type 1 (bare-metal) hypervisor places the hypervisor software directly on the server hardware. This removes the host operating system layer completely, allowing the hypervisor's virtual switch to interact directly with physical hardware NIC drivers and CPU schedulers for maximum throughput and minimum latency.

Step-by-Step Solution

1
Analyze the existing virtualization platform architecture.
Identified that the current environment uses a Type 2 (hosted) hypervisor running on top of a general-purpose host OS (Linux).
Type 2 hypervisors depend on the underlying host OS to manage hardware access, CPU scheduling, and physical device drivers, creating network latency and processing bottlenecks.
2
Identify the hypervisor architecture designed for bare-metal hardware control.
A Type 1 (bare-metal) hypervisor runs directly on physical hardware without requiring a separate host operating system.
Type 1 hypervisors incorporate lightweight management kernels that handle CPU, memory, and physical network interface scheduling directly, yielding higher efficiency and lower latency.
3
Select the appropriate migration path.
Migrating to a Type 1 hypervisor architecture removes the host OS layer entirely.
Direct access to physical hardware drivers and integrated virtual switching inside a Type 1 hypervisor eliminates kernel-level context switching between host OS and hypervisor.

Key Concept

Type 1 vs Type 2 Hypervisor Architecture
Estimated Time:1m 30s
Question 905Question →

An administrator is documenting the 802.11 wireless architecture for a corporate office. Which identifier uniquely distinguishes a specific Basic Service Set (BSS) operating on an access point radio at the Layer 2 data link layer?

Show answer & explanation

Answer: The MAC address of the access point's radio interface (BSSID)

Answer

The MAC address of the access point's radio interface (BSSID) uniquely identifies a specific Basic Service Set (BSS).
The correct answer identifies the Basic Service Set Identifier (BSSID), which is the 48-bit MAC address of the access point radio serving a specific wireless cell (BSS). In 802.11 networks, this hardware address uniquely distinguishes frame traffic sent to or from that particular radio.

Step-by-Step Solution

1
Identify the standard 802.11 terminology for wireless service sets and their unique identifiers.
A Basic Service Set (BSS) consists of a single access point radio and its associated clients.
Understanding the fundamental building blocks of Wi-Fi coverage cells is necessary for network identification.
2
Determine which parameter acts as the Layer 2 hardware address for a BSS.
The Basic Service Set Identifier (BSSID) is used at Layer 2 and corresponds directly to the 48-bit MAC address of the AP radio servicing that BSS.
Wireless client frames use the BSSID MAC address in 802.11 frame headers to target a specific AP radio.

Key Concept

Basic Service Set Identifier (BSSID) in 802.11 Wireless Architecture
Estimated Time:45s
Question 906Question →

A network administrator is configuring SLAAC on a router interface for a host with the MAC address `0012.3456.789A`. What is the 64-bit interface identifier generated using the EUI-64 process?

Show answer & explanation

Answer: 0212:34ff:fe56:789a

Answer

The correct interface identifier is 0212:34ff:fe56:789a.
The EUI-64 calculation process requires splitting the 48-bit MAC address (00:12:34:56:78:9A) into two equal halves, inserting FFFE in the middle (0012:34FF:FE56:789A), and flipping the 7th bit of the first byte (00000000 becomes 00000010, or 02 in hex). This yields 0212:34ff:fe56:789a.

Step-by-Step Solution

1
Split the 48-bit MAC address into two 24-bit halves.
Left half: 00:12:34, Right half: 56:78:9A
EUI-64 requires inserting a 16-bit payload between the Organizationally Unique Identifier (OUI) and the NIC-specific portion.
2
Insert FFFE between the two halves.
00:12:34:FF:FE:56:78:9A
This expands the 48-bit MAC address into a 64-bit value.
3
Invert the 7th bit (Universal/Local bit) of the first byte.
First byte 00 (00000000 in binary) becomes 02 (00000010 in binary). Resulting string: 02:12:34:FF:FE:56:78:9A
Inverting the 7th bit indicates that the address is globally unique.
4
Format the resulting 64-bit value into four 16-bit IPv6 hextets.
0212:34ff:fe56:789a
Standard IPv6 address notation groups 16-bit blocks separated by colons.

Key Concept

EUI-64 Interface Identifier Generation
Estimated Time:45s
Question 907Question →

Match each enterprise network infrastructure component on the left with its primary operational role on the right.

Click a left item, then click its matching right item

Items

Router
Layer 2 Switch
Next-Generation Firewall (NGFW)
Wireless LAN Controller (WLC)

Matches

Show answer & explanation

Answer

Router connects distinct IP subnets using routing tables; Layer 2 Switch forwards local frames based on MAC addresses; Next-Generation Firewall performs deep packet inspection up to Layer 7; Wireless LAN Controller centrally manages lightweight access points.
Each network device performs a specialized role within an enterprise architecture: Routers route IP packets across subnets, Layer 2 Switches switch local Ethernet frames using MAC addresses, Next-Generation Firewalls inspect application payload data for security, and Wireless LAN Controllers centralize management for lightweight APs.

Step-by-Step Solution

1
Identify the primary role of a Router.
Routers operate at Layer 3 and forward packets between different IP networks and subnets based on destination IP address routing decisions.
Connecting separate networks and determining path selection is the fundamental function of a router.
2
Identify the primary role of a Layer 2 Switch.
Layer 2 switches maintain a MAC address table to switch frames within a single local network/VLAN.
Layer 2 switches isolate collision domains but operate entirely within one broadcast domain.
3
Identify the primary role of a Next-Generation Firewall (NGFW).
NGFWs analyze traffic context and application content from Layer 4 up through Layer 7 to enforce security controls.
Deep packet inspection and application awareness distinguish NGFWs from standard stateful firewalls.
4
Identify the primary role of a Wireless LAN Controller (WLC).
WLCs act as the centralized intelligence hub to manage configuration, security policies, and radio frequencies for lightweight APs.
Split-MAC architectures offload management tasks from APs to the controller.

Key Concept

Primary operational roles of core network components
Question 908Question →

An enterprise network switch, Switch-A, is connected to Switch-B via interface GigabitEthernet0/1. Switch-A is configured with `switchport mode dynamic desirable` and `switchport trunk native vlan 50`. Switch-B is configured with `switchport mode dynamic auto` and `switchport trunk native vlan 1`. Spanning Tree Protocol (STP) and Cisco Discovery Protocol (CDP) are enabled on both switches. Which TWO operational outcomes occur on this interswitch link? (Select TWO.)

Select all that apply

Show answer & explanation

Answer: The interface operational mode successfully negotiates to an IEEE 802.1Q trunk link.; CDP generates periodic console messages warning of a native VLAN mismatch between the switches.

Answer

The interswitch link successfully negotiates an operational IEEE 802.1Q trunk via DTP, and CDP periodically logs native VLAN mismatch notifications.
An IEEE 802.1Q trunk forms successfully because a port configured as dynamic desirable actively negotiates with a port in dynamic auto mode. Additionally, because Switch-A defines VLAN 50 as native while Switch-B defines VLAN 1 as native, CDP detects the inconsistency through TLV messages and generates native VLAN mismatch warnings.

Step-by-Step Solution

1
Analyze the Dynamic Trunking Protocol (DTP) operational modes configured on both ends of the link.
Switch-A (`dynamic desirable`) actively sends DTP frames, and Switch-B (`dynamic auto`) listens and responds.
The combination of dynamic desirable and dynamic auto results in successful trunk negotiation.
2
Analyze IEEE 802.1Q native VLAN egress tagging and ingress processing behavior.
Switch-A sends VLAN 50 frames untagged, while Switch-B expects native VLAN traffic on VLAN 1 untagged.
By default, 802.1Q trunks transmit frames belonging to the configured native VLAN without an 802.1Q header.
3
Evaluate Layer 2 discovery protocol diagnostics for native VLAN consistency.
CDP exchanges native VLAN information via TLVs, detects the mismatch (VLAN 50 vs VLAN 1), and logs `%CDP-4-NATIVE_VLAN_MISMATCH` console messages.
CDP continuously monitors interswitch link parameters to highlight Layer 2 misconfigurations.

Key Concept

DTP operational mode negotiation and IEEE 802.1Q native VLAN mismatch behavior
Question 909Question →

A network engineer is analyzing physical radio frequency (RF) propagation behaviors in an enterprise campus facility. Match each RF propagation phenomenon on the left with its corresponding physical behavior or operational impact on the right.

Click a left item, then click its matching right item

Items

Absorption
Reflection
Refraction
Diffraction

Matches

Show answer & explanation

Answer

Absorption pairs with RF energy conversion into heat within dense materials; Reflection pairs with signal bouncing off smooth conductive surfaces; Refraction pairs with wave bending across changing media densities; Diffraction pairs with wave bending around sharp edges of solid obstacles.
Each RF propagation phenomenon describes a distinct physical interaction between wireless signals and environmental structures. Absorption dissipates signal power as heat through materials; Reflection bounces waves off smooth conductive barriers; Refraction bends light and radio waves across atmospheric or density gradients; Diffraction curves waves around sharp obstacle borders.

Step-by-Step Solution

1
Identify the characteristic of RF Absorption.
Absorption relates directly to energy loss converted into heat within dense physical obstacles like walls.
Dense matter absorbs RF energy, causing direct attenuation.
2
Identify the characteristic of RF Reflection.
Reflection involves RF signals bouncing off large, smooth metallic surfaces.
Conductive surfaces reflect electromagnetic waves, leading to multipath signal paths.
3
Identify the characteristic of RF Refraction.
Refraction describes signal bending caused by variations in propagation media density.
Velocity changes across media boundaries shift the phase and angle of the wave.
4
Identify the characteristic of RF Diffraction.
Diffraction describes signal bending around sharp physical corners or through small openings.
Obstacle edges split and distort the wavefront, creating shadow areas behind the obstacle.

Key Concept

RF Propagation Phenomena and Signal Impairments
Question 910Question →

An enterprise network architecture incorporates multiple specialized physical and virtual components across campus, data center, and edge segments. Match each network component on the left to its primary operational function and forwarding behavior on the right.

Click a left item, then click its matching right item

Items

Next-Generation Firewall (NGFW)
Type 1 Bare-Metal Hypervisor
Wireless LAN Controller (WLC)
Layer 3 Switch

Matches

Show answer & explanation

Answer

Next-Generation Firewall (NGFW) matches deep packet inspection up to Layer 7 stateful security enforcement. Type 1 Bare-Metal Hypervisor matches direct hardware execution for managing virtual machines and vSwitches. Wireless LAN Controller (WLC) matches centralized control-plane and dynamic RF management for lightweight APs. Layer 3 Switch matches ASIC-driven, wire-speed inter-VLAN hardware routing.
Each component is accurately paired with its architectural plane and operational behavior: Next-Generation Firewalls handle stateful Layer 7 security inspection; Type 1 Hypervisors execute on bare metal to manage compute virtualization and vSwitches; Wireless LAN Controllers centralize control-plane RF and policy administration for APs; and Layer 3 Switches perform ASIC-accelerated inter-VLAN packet routing at line rate.

Step-by-Step Solution

1
Analyze the functional boundaries of security appliances.
Identify that Next-Generation Firewalls perform stateful inspection and Layer 7 application inspection rather than basic packet switching.
Security components operate on security zone boundaries to filter traffic based on application signature and state.
2
Distinguish host virtualization architecture from traditional operating systems.
Map the Type 1 hypervisor directly to bare hardware management and internal vSwitch forwarding.
Type 1 hypervisors execute without an underlying host OS, managing compute and virtual network resources directly.
3
Examine wireless centralized control architecture.
Associate the Wireless LAN Controller with centralized control plane tasks, dynamic RF management, and provisioning for lightweight APs.
Split-MAC architecture delegates real-time frame handling to lightweight APs while offloading management and control functions to the WLC.
4
Evaluate LAN routing hardware mechanics.
Connect the Layer 3 switch with ASIC-accelerated inter-VLAN routing.
Layer 3 switches utilize hardware ASICs to route packets between VLANs at line rate with significantly lower latency than software-based routers.

Key Concept

Enterprise Network Component Roles and Functional Boundaries
Question 911Question →

Match each Cisco Split-MAC architecture component or CAPWAP feature on the left with its primary function or operational characteristic on the right.

Click a left item, then click its matching right item

Items

Lightweight Access Point (LAP)
Wireless LAN Controller (WLC)
CAPWAP Control Tunnel
CAPWAP Data Tunnel

Matches

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Answer

Lightweight Access Point (LAP) matches with handling real-time MAC functions like beacons and probe responses. Wireless LAN Controller (WLC) matches with handling management MAC functions like client authentication and association. CAPWAP Control Tunnel matches with exchanging encrypted management messages over UDP port 5246. CAPWAP Data Tunnel matches with carrying client data traffic over UDP port 5247.
Each component correctly pairs with its role in Cisco centralized wireless deployment: LAPs handle real-time RF MAC duties locally; WLCs handle management MAC functions centrally; CAPWAP Control operates on UDP port 5246 with DTLS encryption; and CAPWAP Data carries client payload packets over UDP port 5247.

Step-by-Step Solution

1
Identify the responsibilities assigned to the Lightweight Access Point (LAP) under Cisco Split-MAC architecture.
Real-time operations directly affecting radio hardware (such as beaconing, probe responses, and MAC layer encryption/decryption) are processed locally by the LAP.
Real-time MAC tasks require microsecond latency, making transmission across a WAN or LAN to a central WLC impractical.
2
Identify the responsibilities assigned to the Wireless LAN Controller (WLC).
Management and control plane tasks (such as 802.11 authentication, association handling, frame translation, and quality of service policy enforcement) are processed centrally by the WLC.
Centralizing management MAC tasks simplifies policy enforcement and wireless network administration across multiple APs.
3
Differentiate between CAPWAP Control and CAPWAP Data transport characteristics.
Control traffic uses UDP port 5246 (secured with DTLS), while Data traffic uses UDP port 5247.
Separating control and data plane transport protocols allows independent security, QoS, and routing mechanisms for management versus client payload traffic.

Key Concept

Cisco Split-MAC Architecture and CAPWAP Protocols
Estimated Time:1m 30s
Question 912Question →

A Cisco Catalyst switch with an initially empty MAC address table receives an Ethernet frame on ingress port FastEthernet0/1. The frame originates from Host A (MAC address 00A1.1111.AAAA) and is addressed to Host B (MAC address 00B2.2222.BBBB) on VLAN 10. In what chronological sequence does the Layer 2 switch execute internal processing steps from frame ingress to frame egress?

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence is: 1) Parse ingress frame for MAC addresses, 2) Learn source MAC and map to ingress port, 3) Lookup destination MAC in table, 4) Identify destination as unknown unicast, 5) Flood frame out all VLAN ports except ingress port.
When a Layer 2 switch receives an Ethernet frame on an ingress interface, it processes the frame in a specific order: first, it parses the L2 header; second, it reads the source MAC address and updates/populates its MAC address table (CAM table); third, it looks up the destination MAC address; fourth, if the destination is missing from the CAM table, it classifies it as an unknown unicast; fifth, it floods the frame out all active ports assigned to that VLAN except the receiving port.

Step-by-Step Solution

1
Receive and ingress-parse frame
Identified Source MAC: 00A1.1111.AAAA, Destination MAC: 00B2.2222.BBBB, Ingress Port: Fa0/1, VLAN: 10.
The switch ASIC must inspect the Layer 2 Ethernet header preamble and fields first.
2
Source MAC Learning
MAC table entry updated with [VLAN 10 | 00A1.1111.AAAA | Dynamic | Fa0/1].
Layer 2 switches always learn source MAC addresses before determining egress forwarding.
3
Destination MAC Lookup
Query for 00B2.2222.BBBB yields no matching entry in VLAN 10 CAM table.
Switch determines whether to perform known unicast forwarding or unknown unicast flooding.
4
Classification of Traffic
Traffic categorized as unknown unicast.
A table miss forces the switch to default to broadcast-like flooding behavior within Layer 2 bounds.
5
Egress Frame Flooding
Frame replicated to all operational VLAN 10 ports, suppressing Fa0/1.
Split-horizon rule prevents sending a frame back out the interface from which it was received.

Key Concept

Layer 2 MAC Address Table Operation and Ingress/Egress Forwarding Pipeline
Question 913Question →

Match each IPv6 address, prefix, or protocol scenario on the left with its corresponding IPv6 address representation or reserved prefix range on the right.

Click a left item, then click its matching right item

Items

The dynamically generated IPv6 link-local address for an interface with MAC address `00:1A:2B:3C:4D:5E` using EUI-64
The IPv6 prefix block defined by RFC 4193 for locally assigned Unique Local Addresses (ULA) using a 40-bit random Global ID
The link-local IPv6 multicast address used exclusively to send OSPFv3 packets to Designated Routers (DR) and Backup Designated Routers (BDR)
The IPv6 prefix representation used in routing tables to designate the default route

Matches

Show answer & explanation

Answer

The SLAAC EUI-64 calculation matches `fe80::21a:2bff:fe3c:4d5e`; the locally assigned ULA prefix matches `fd00::/8`; the OSPFv3 DR/BDR multicast address matches `ff02::6`; and the default route matches `::/0`.
Each item accurately maps to its IPv6 address representation: EUI-64 requires inserting FFFE and flipping the 7th bit (`fe80::21a:2bff:fe3c:4d5e`); RFC 4193 local ULA uses `fd00::/8`; OSPFv3 DR/BDR communication uses `ff02::6`; and the default route is `::/0`.

Step-by-Step Solution

1
Calculate the SLAAC EUI-64 link-local address
`fe80::21a:2bff:fe3c:4d5e`
Split MAC `00:1A:2B:3C:4D:5E`, insert `FF:FE` to form `001A:2BFF:FE3C:4D5E`, flip the 7th bit of byte 1 (`00` to `02`), and prepend `fe80::`.
2
Identify the RFC 4193 locally assigned ULA prefix
`fd00::/8`
Bit 8 of the `fc00::/7` block is set to 1 for locally generated 40-bit random Global IDs, fixing the prefix to `fd00::/8`.
3
Determine the OSPFv3 DR/BDR multicast address
`ff02::6`
`ff02::5` is sent to All OSPF Routers, whereas `ff02::6` targets All OSPF Designated Routers.
4
Identify the default route IPv6 prefix
`::/0`
`::/0` signifies all zeros address and zero prefix length, serving as the default match in IPv6 routing.

Key Concept

IPv6 Addressing Scopes, EUI-64 Conversion Rules, and Multicast / Routing Prefixes
Question 914Question →

A switch interface configured as an IEEE 802.1Q trunk receives an Ethernet frame that does not contain a 4-byte 802.1Q VLAN tag. How does the switch process this incoming frame?

Show answer & explanation

Answer: It assigns the frame to the native VLAN configured on the trunk port.

Answer

The switch assigns the untagged frame to the native VLAN configured on the trunk port.
Under IEEE 802.1Q trunking standards, traffic belonging to the configured native VLAN is transmitted across the trunk link without inserting a 4-byte VLAN tag. When an untagged frame arrives at an 802.1Q trunk interface, the receiving switch assigns that frame to its configured native VLAN.

Step-by-Step Solution

1
Examine frame encapsulation on the 802.1Q trunk link.
Identify that the incoming frame lacks a 4-byte 802.1Q VLAN tag header.
802.1Q trunking transmits and receives native VLAN traffic without appending a VLAN tag.
2
Apply 802.1Q native VLAN processing rules.
Map the untagged frame to the native VLAN assigned to the trunk interface.
Standard 802.1Q mechanics dictate that untagged frames arriving on a trunk interface belong to the configured native VLAN.

Key Concept

802.1Q Native VLAN untagged frame handling
Question 915Question →

Match each RFC 1918 private IPv4 address prefix block to its corresponding scope and address range definition.

Click a left item, then click its matching right item

Items

10.0.0.0/8
172.16.0.0/12
192.168.0.0/16

Matches

Show answer & explanation

Answer

10.0.0.0/8 matches a single Class A network block (10.0.0.0 - 10.255.255.255); 172.16.0.0/12 matches 16 contiguous Class B network blocks (172.16.0.0 - 172.31.255.255); 192.168.0.0/16 matches 256 contiguous Class C network blocks (192.168.0.0 - 192.168.255.255).
RFC 1918 explicitly defines three private address blocks: one Class A block (10.0.0.0/8), 16 contiguous Class B blocks (172.16.0.0/12, spanning 172.16.0.0 to 172.31.255.255), and 256 contiguous Class C blocks (192.168.0.0/16, spanning 192.168.0.0 to 192.168.255.255).

Step-by-Step Solution

1
Identify the RFC 1918 range and structure for Class A private addressing.
10.0.0.0/8 covers addresses from 10.0.0.0 through 10.255.255.255, representing a single Class A block.
RFC 1918 allocates one /8 block for Class A private networks.
2
Identify the RFC 1918 range and structure for Class B private addressing.
172.16.0.0/12 covers addresses from 172.16.0.0 through 172.31.255.255, forming 16 contiguous Class B (/16) blocks.
RFC 1918 allocates 16 contiguous /16 blocks starting at 172.16.0.0 up to 172.31.255.255.
3
Identify the RFC 1918 range and structure for Class C private addressing.
192.168.0.0/16 covers addresses from 192.168.0.0 through 192.168.255.255, forming 256 contiguous Class C (/24) blocks.
RFC 1918 allocates 256 contiguous /24 blocks starting at 192.168.0.0 up to 192.168.255.255.

Key Concept

RFC 1918 Private IPv4 Address Space Allocation
Question 916Question →

Two Cisco Catalyst switches, Switch-1 and Switch-2, are connected directly via their GigabitEthernet0/1 interfaces. Switch-1 is configured with `switchport trunk native vlan 99` and `switchport trunk allowed vlan 10,20,99`. Switch-2 is configured with `switchport trunk native vlan 10` and `switchport trunk allowed vlan 10,20,99`. A workstation connected to an access port in VLAN 99 on Switch-1 transmits an untagged broadcast frame. Assuming both trunk ports are operational, how will Switch-2 process this frame upon receiving it over the trunk link?

Show answer & explanation

Answer: Switch-2 accepts the untagged frame, assigns it to its own configured native VLAN (VLAN 10), and forwards it to ports within VLAN 10.

Answer

Switch-2 accepts the untagged frame, assigns it to its own configured native VLAN (VLAN 10), and forwards it to ports within VLAN 10.
Under IEEE 802.1Q trunking rules, frames belonging to the trunk's native VLAN are transmitted untagged. Switch-1 transmits the VLAN 99 broadcast frame without an 802.1Q tag because VLAN 99 is its local native VLAN. When Switch-2 receives this untagged frame on its trunk interface, it associates the frame with its own configured native VLAN (VLAN 10). As a result, the frame is processed within VLAN 10 on Switch-2, causing cross-VLAN traffic leakage.

Step-by-Step Solution

1
Analyze frame egress from Switch-1
Switch-1 receives the broadcast in VLAN 99. Because VLAN 99 is configured as the native VLAN on Switch-1's trunk interface, Switch-1 strips/omits the 802.1Q header tag and sends the frame untagged across the trunk link.
By definition in IEEE 802.1Q, traffic belonging to the native VLAN is transmitted across a trunk without an inserted 4-byte 802.1Q VLAN tag.
2
Analyze frame ingress at Switch-2
Switch-2 receives an untagged Ethernet frame on its trunk interface GigabitEthernet0/1.
The frame arrives without any 802.1Q tag identifying its originating VLAN.
3
Apply native VLAN ingress mapping logic on Switch-2
Switch-2 maps the incoming untagged frame to its local native VLAN, which is VLAN 10.
A switch trunk interface always associates untagged incoming frames with its own locally configured native VLAN setting.
4
Determine forwarding domain
The broadcast frame is flooded to all operational access ports in VLAN 10 on Switch-2.
Traffic sent on VLAN 99 on Switch-1 leaks directly into VLAN 10 on Switch-2 due to the native VLAN mismatch.

Key Concept

IEEE 802.1Q Native VLAN Ingress/Egress Processing and Mismatch Behavior
Question 917Question →

Match each network architecture layer or topology design model on the left to its correct functional responsibility or operational trait on the right.

Click a left item, then click its matching right item

Items

Spine Layer (Data Center Spine-Leaf)
Leaf Layer (Data Center Spine-Leaf)
Distribution Layer (Traditional 3-Tier Campus)
Collapsed Core Layer (2-Tier Campus)

Matches

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Answer

Spine Layer matches high-speed L3 ECMP backbone forwarding; Leaf Layer matches endpoint attachment and VTEP encapsulation; Distribution Layer matches inter-VLAN routing, ACL filtering, and policy enforcement; Collapsed Core matches combining Core transport and Distribution policy into a single switch tier.
The pairings correctly align each tier with its defining design attributes: Spine switches provide non-blocking ECMP L3 transport; Leaf switches act as endpoint connection points and VTEPs; Distribution switches manage L2/L3 policy, ACLs, and routing boundaries; Collapsed Core switches combine Core and Distribution capabilities into one physical tier.

Step-by-Step Solution

1
Analyze Spine Layer responsibilities in Data Center Spine-Leaf (Clos) design.
Spine switches strictly interconnect Leaf switches, run L3 routing protocols, and provide equal-cost multipath transport without inter-spine links.
Spine nodes form the high-speed backbone core of the Clos fabric.
2
Analyze Leaf Layer responsibilities in Spine-Leaf design.
Leaf switches connect to servers, storage, and firewalls, serving as the edge access and VTEP overlay encapsulation boundary.
Endpoints attach exclusively to Leaf nodes in modern fabric architectures.
3
Analyze Distribution Layer responsibilities in traditional 3-Tier Campus design.
Distribution switches aggregate Access switches, perform inter-VLAN routing, and enforce security ACLs and QoS policies.
The Distribution tier isolates the Access tier from the Core tier and manages network policies.
4
Analyze Collapsed Core (2-Tier) campus design characteristics.
Collapsed Core integrates Distribution policy routing and Core high-speed switching into one combined physical tier.
It simplifies deployment for smaller networks that do not require separate core and distribution switch chassis.

Key Concept

Enterprise Campus (3-Tier & Collapsed Core) vs. Data Center (Spine-Leaf) Architectural Layers
Question 918Question →

A network technician connects SwitchA and SwitchB using interface GigabitEthernet1/0/1 on both devices. Auto-MDIX has been manually disabled on both switch ports. The technician executes `show interfaces gigabitethernet 1/0/1` on SwitchA and observes the following CLI output:

SwitchA# show interfaces gigabitethernet 1/0/1
GigabitEthernet1/0/1 is down, line protocol is down
Hardware is Gigabit Ethernet, address is 0007.7d0e.a101 (bia 0007.7d0e.a101)
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-duplex, Auto-speed

Which underlying physical layer issue is causing the interface status and line protocol to both remain in the down state?

Show answer & explanation

Answer: A straight-through Ethernet cable is connected between similar switch interfaces while Auto-MDIX is disabled.

Answer

A straight-through Ethernet cable is connected between similar switch interfaces while Auto-MDIX is disabled.
When connecting two switches directly (like devices operating MDI-X to MDI-X), a crossover cable is required to connect transmit pins to receive pins. When Auto-MDIX is disabled, using a straight-through cable prevents the interfaces from detecting physical signals, keeping the status and line protocol down.

Step-by-Step Solution

1
Analyze the CLI output line status and line protocol.
Both interface status and line protocol report 'down', indicating a Layer 1 physical signal loss or cable issue.
When line status is down, the interface fails to detect electrical or optical carrier signals from the remote end.
2
Evaluate the cabling requirements for like-device connections without Auto-MDIX.
Switch-to-switch connections use MDI-X pinouts on both ends; without Auto-MDIX, a crossover cable is required.
A straight-through cable connects TX pins on SwitchA to TX pins on SwitchB and RX pins to RX pins, preventing physical carrier detection.

Key Concept

Physical interface troubleshooting and Auto-MDIX dependency on crossover vs straight-through cabling.
Estimated Time:1m 30s
Question 919Question →

An enterprise network operations team is replacing a legacy 3-Tier campus architecture with a 2-Tier Spine-Leaf (Clos) topology in their data center to optimize East-West traffic performance for containerized microservices. Which of the following architectural characteristics and operational design principles correctly describe this Spine-Leaf fabric when compared to the traditional 3-Tier model? (Select TWO.)

Select all that apply

Show answer & explanation

Answer: Every Leaf switch connects to every Spine switch in a full mesh layout, guaranteeing a deterministic two-hop latency path for inter-leaf traffic.; Equal-Cost Multi-Pathing (ECMP) routing is implemented across Layer 3 uplinks to enable active-active load sharing without Spanning Tree Protocol port blocking.

Answer

The correct statements are that every Leaf switch connects directly to every Spine switch to provide a deterministic two-hop path for inter-leaf traffic, and that Layer 3 routing with Equal-Cost Multi-Pathing (ECMP) enables active-active load balancing across uplinks without Spanning Tree Protocol link blocking.
In a 2-Tier Spine-Leaf fabric, every Leaf switch connects directly to every Spine switch without horizontal intra-tier links. This structural layout provides a predictable two-hop transport path for East-West traffic across Leaf switches. Furthermore, deploying Layer 3 routing with Equal-Cost Multi-Pathing (ECMP) allows active-active forwarding across all Leaf-Spine links, eliminating Spanning Tree Protocol blocking.

Step-by-Step Solution

1
Analyze physical cabling topology constraints in a 2-Tier Spine-Leaf (Clos) architecture.
Verify that Spine-Leaf requires every Leaf node to connect to every Spine node, with zero direct links between nodes of the same tier.
This bipartite graph layout ensures a predictable, fixed path length of exactly two hops (Leaf to Spine to Leaf) for any East-West communication.
2
Evaluate control plane mechanisms and bandwidth utilization across the fabric.
Determine that Layer 3 routing combined with ECMP replaces Layer 2 Spanning Tree Protocol loop-prevention mechanisms.
ECMP utilizes all available uplinks simultaneously in an active-active forwarding state, avoiding the bandwidth degradation caused by STP port blocking.
3
Differentiate device roles and boundary placements between Leaf and Spine switches.
Confirm that end-system access ports and broadcast domain boundaries reside strictly on Leaf switches, while Spine switches act solely as high-speed transport infrastructure.
Isolating Spine switches from direct host connectivity and Layer 2 broadcast domains keeps the core stateless, fast, and scalable.

Key Concept

2-Tier Spine-Leaf (Clos) Architecture Characteristics vs 3-Tier Campus Design
Question 920Question →

A network engineer is auditing infrastructure hardware and operational roles across an enterprise campus network. Match each network component on the left with its primary operational function on the right.

Click a left item, then click its matching right item

Items

Core Switch
Access Switch
Lightweight Access Point (LAP)
Enterprise Router

Matches

Show answer & explanation

Answer

Core Switch matches high-speed backbone transport without heavy filtering; Access Switch matches connecting endpoints and enforcing port security; Lightweight Access Point matches real-time 802.11 processing with central controller management; Enterprise Router matches path determination between IP subnets and broadcast domain termination.
Each component is correctly matched to its standard Cisco three-tier hierarchical architecture role or split-MAC wireless model: Core switches provide low-latency backbone transport; Access switches connect endpoints; Lightweight APs process 802.11 frames while managed by a central controller; Routers make Layer 3 forwarding decisions between subnets and isolate broadcast domains.

Step-by-Step Solution

1
Identify the primary role of the Core Switch
Matched to high-speed backbone transport with minimal overhead.
Core devices prioritize raw switching speed and low latency across the network backbone.
2
Identify the primary role of the Access Switch
Matched to end-user device connectivity and edge port security.
Access switches represent the entry point for endpoint devices and enforce boundary policies.
3
Identify the primary role of the Lightweight Access Point (LAP)
Matched to handling real-time 802.11 wireless traffic offloading control to a WLC.
Split-MAC architecture assigns real-time wireless tasks to the LAP and management to the WLC.
4
Identify the primary role of the Enterprise Router
Matched to inter-subnet path determination and broadcast domain isolation.
Routers operate at Layer 3 to connect distinct networks and block Layer 2 broadcast frames.

Key Concept

Hierarchical network layers and specialized device roles (Core, Access, LAP split-MAC, and Layer 3 Routing).
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