Free Cisco 400-007 Practice Exam with Questions & Answers

ChatGPT said:???? QUESTION NO: 391

[Main Topic: Scenario-Based Design Strategy Guidance]

Feature-rich and attributed networks are used to model complex systems where nodes and links can represent various relationships and characteristics. Which two alternative network models can be used to model interactions over time or by specific relationships?

A. heterogeneous network

B. information network

C. location-aware network

D. multilayer network

E. probabilistic network

F. temporal network

Answer: D, F

???? Comprehensive Explanation:

D. Multilayer Network:This model captures different types of relationships or interactions by separating them into layers. Each layer can represent a specific attribute (e.g., organizational structure, communication paths, or access levels), enabling a more granular view of network behaviors or dependencies.

F. Temporal Network:A temporal network models interactions over time by including timestamps or time intervals for each interaction or link. It’s well-suited for analyzing dynamic behaviors such as traffic flow, communication logs, or transaction timelines.

Other options:

❌ A. Heterogeneous Network: Refers to networks composed of different technologies or platforms, not necessarily different types of attributes or timelines.

❌ B. Information Network: This is a general term and does not specifically define a structured modeling approach for attributes or time.

❌ C. Location-Aware Network: Involves geolocation or spatial data but does not inherently model time or multi-attribute structures.

❌ E. Probabilistic Network: Uses probability distributions to model uncertain events, not ideal for modeling time or attributes.

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???? QUESTION NO: 392

[Main Topic: Business-Driven Design Approaches]

A company is assessing their technology landscape before moving to the cloud. They observe that over 5000 servers have less than 50% capacity utilization. What cloud architecture model best supports optimizing resource utilization?

A. homogenous cloud

B. heterogenous cloud

C. hybrid-private cloud

D. public cloud

Answer: D

???? Comprehensive Explanation:

D. Public Cloud:Public cloud services provide elastic and scalable infrastructure. For workloads with low or variable utilization, public cloud offers pay-as-you-go models that significantly reduce the overhead of underutilized on-prem hardware. This is ideal for shifting capital expenditure (CAPEX) to operational expenditure (OPEX), achieving better cost efficiency.

Other options:

❌ A. Homogenous Cloud: Not a standard term; it might imply uniform hardware/software environments, but it doesn’t address utilization.

❌ B. Heterogenous Cloud: Typically used to describe mixed environments but doesn’t directly offer utilization optimization.

❌ C. Hybrid-Private Cloud: Offers flexibility and data control but still often involves maintaining some level of underused on-prem resources unless carefully managed.

EIGRP’s convergence time is heavily impacted by the size of the query domain — the group of routers involved when a route goes into active state. The larger the query domain, the longer the convergence. Summarization naturally bounds query propagation because routers receiving a summary have no knowledge of individual prefixes beyond that summary, preventing them from being queried about specifics they don’t track.

This design technique is emphasized in CCDE v3.1 because:

Summarization reduces the query scope.

Faster convergence happens as fewer routers process queries.

Hierarchical design is enabled for stability and scalability.

Why other options are incorrect:

A: Distribute lists filter prefixes but don ' t reduce query propagation.

B and C: Triangulated or squared physical topology doesn’t control protocol-level query scope.

E: Default routes may help limited routing domains but don’t optimize EIGRP convergence specifically.

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A (PPDIOO - Prepare, Plan, Design, Implement, Operate, Optimize):PPDIOO is Cisco’s structured lifecycle methodology designed specifically for network design, deployment, and management. It ensures continuous improvement, iterative design, and aligns technical efforts with business goals throughout the entire network lifecycle.

Other options explained:

B: Waterfall is a generic software development methodology.

C: Spiral emphasizes iterative risk management for software development.

D: V model applies primarily to software verification and validation.

C (Scalable):For rapidly growing or contracting businesses, scalability is the highest priority to ensure that the network can adapt to changes in size, services, and demand without major redesigns.

Other options explained:

A: Hierarchical design improves structure but does not guarantee scalability.

B: Modularity aids scalability but is a design approach, not the ultimate priority.

D: A dedicated core is part of hierarchical designs but not always essential for startups.

C (Lack of visibility and tracking): In cloud-native environments, organizations often struggle with monitoring and tracking workloads across dynamic, distributed, and multi-tenant architectures. Traditional visibility tools may not fully cover cloud-native assets like containers, serverless functions, or microservices, making it harder to detect threats and enforce policies.

D (Increased attack surface): Cloud-native architectures introduce many additional components—APIs, microservices, third-party integrations, and distributed data—which all expand the organization ' s overall attack surface. More entry points for attackers create additional security challenges compared to traditional on-prem environments.

Other options explained:

A: User roles can be managed with proper IAM systems.

B: Polymorphism refers to code behavior in programming, not a core security challenge in cloud-native design.

E: Credential validation is part of basic access control but not a top cloud-native challenge compared to visibility and attack surface expansion.

D (L1/L2 for ABRs and L1 for internal routers):This hierarchical approach minimizes LSDB size inside areas (L1 routers only maintain intra-area routes) while L1/L2 routers handle inter-area route propagation, reducing neighbor adjacencies and improving scalability.

Other options explained:

A: Level 2 everywhere results in larger LSDBs across all routers.

B: Only L2 routers at ABRs would isolate L1 domains improperly.

C: Pure L1 design prevents inter-area reachability.

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????  Comprehensive Explanation:

A: In hybrid WAN designs where routing domains are gradually migrating from OSPF to BGP, particularly with overlapping domains or redistribution points, loops can occur if the same routes are seen via multiple protocols (e.g., BGP and OSPF). Implementing route filtering on the OSPF backbone prevents it from learning and advertising spoke routes that it also receives via BGP—eliminating the loop scenario.

B: Advertising a low administrative distance (AD) for transit traffic does not prevent loops and may worsen convergence or cause routing inconsistency.

C: Summarizing OSPF routes may reduce the routing table size, but it does not solve the loop issue caused by dual protocol redistribution unless filtering is applied.

D: Redistributing EIGRP routes into BGP with a low cost might cause preference toward one path but does not address the loop risk between the hybrid segments (OSPF and BGP).

This is a classic use case for route filtering in dual-protocol or dual-backbone migrations, where ensuring consistent path selection and loop prevention is essential.

????  QUESTION NO: 356 [Network Architecture Principles]

A network becomes unintentionally segmented when remote sites connect to HQ only via the public Internet. Which option helps de-segment the network?

A. Build virtual networks that pass over the network

B. Mark traffic for special handling through quality of service

C. Configure little to no control data plane policy

D. Block specific sources from reaching specific destinations

Answer: A

????  Explanation:

A: Virtual networks (e.g., VPNs, tunnels) create secure, logical overlays across segmented physical infrastructure such as the public Internet, effectively re-integrating remote sites into the corporate network. This re-establishes end-to-end connectivity and consistent routing/security policies.

Other options:

B: QoS does not address segmentation or connectivity.

C: Lax control-plane policies do not restore logical network integration and may increase security risk.

D: Blocking traffic further limits connectivity and exacerbates segmentation.

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????  QUESTION NO: 357 [Protocol Design Implications]

You want to add 900 VLANs to an existing 90 in a data center. What are two spanning tree concerns to consider?

A. STP is increased by a factor of 10 convergence time

B. To add 990 VLANs to the switching hardware, reserved VLANs require using extended VLAN

C. The diameter of the STP topology is increased

D. The PVST+ increases CPU utilization

E. BPDU does not support 990 VLANs

Answer: B, D

????  Explanation:

B: Cisco switches reserve certain VLAN IDs. VLANs beyond 1005 are considered extended VLANs and may require special configuration (e.g., VTP transparent mode).

D: Each VLAN with PVST+ has its own instance of STP. Adding 900 more VLANs significantly increases the STP processing overhead on the switch’s control plane and CPU.

Other options:

A: STP convergence time is more dependent on topology than VLAN count.

C: STP diameter is unrelated to the number of VLANs—it ' s a function of hops in the topology.

E: BPDU handling is VLAN-aware under PVST+; there’s no direct per-BPDU VLAN limitation.

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????  QUESTION NO: 358 [Business-Driven Design Approaches]

Which strategic requirement pushes decision-makers toward IaaS over SaaS or PaaS?

A. Selling products and services globally 24/7

B. Integration with partner or vendor supply chains

C. Control over the underlying infrastructure

D. Speed-to-market is more important for an initiative

Answer: C

????  Explanation:

C: IaaS (Infrastructure as a Service) provides the greatest control over compute, storage, and network resources. Organizations that require fine-grained control (e.g., compliance, tuning, OS/hardware) will prefer IaaS over SaaS or PaaS.

Other options:

A and B: These may be satisfied by SaaS or PaaS depending on architecture.

D: PaaS and SaaS often offer faster time-to-market than IaaS.

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????  QUESTION NO: 359 [Security, Automation, and Policy Integration in Design]

To meet PCI-DSS requirements under Strong Access Control Measures, which two conditions must be met?

A. Assign a unique ID to each person with computer access

B. Restrict access to cardholder data on a need-to-know basis

C. Encrypt transmission of cardholder data across open or public networks

D. Each location must require validating PCI compliance if business has multiple locations

E. Protect stored cardholder data

Answer: A, B

????  Explanation:

A: PCI-DSS Requirement 8 mandates that each user have a unique ID to track and control access.

B: PCI-DSS Requirement 7 enforces least privilege—only users with a legitimate business need should access cardholder data.

Other options:

C: This relates to transmission security, not access control.

D: PCI compliance requirements may be managed centrally depending on structure.

E: Protecting stored data is critical but falls under data protection, not access control.

????  QUESTION NO: 360 [Business-Driven Design Approaches / Project Methodologies]

Which project management methodology is characterized by having low client involvement?

A. Traditional project management

B. LEAN project management

C. Kanban project management

D. Agile project management

Answer: A

????  Explanation:

A: Traditional project management (often referred to as the Waterfall model) involves a fixed sequence of phases—planning, design, execution, and delivery. Client involvement is typically high at the beginning (requirements gathering) and low during implementation.

Other options:

B, C, and D (LEAN, Kanban, Agile): These emphasize continuous feedback, flexibility, and frequent customer interaction throughout the project lifecycle. Agile in particular encourages constant client collaboration via sprints and reviews.

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????  QUESTION NO: 361 [Protocol Design Implications / High Availability]

Two routers (R1 and R2) run OSPF and have registered with BFD in asynchronous mode with the echo function enabled. Which two actions occur with the echo function? (Choose two)

A. BFD control packets are sent at a slower pace because the echo function is enabled

B. BFD echo packets are sent from forwarding engines along the Layer 2 path to perform detection

C. BFD control packets are sent at a higher pace because the echo function is enabled

D. Only BFD control packets are sent from forwarding engines along the Layer 2 path to perform detection

E. BFD sessions at either end actively participate in the forwarding of echo packets

Answer: B, E

????  Explanation:

B: BFD echo packets are looped back by the peer and sent through the data plane (forwarding engine) over the actual Layer 2 path. This ensures the link is not only up logically but physically functional.

E: Both ends of the BFD session (R1 and R2) participate in sending/receiving and forwarding echo packets, validating bidirectional liveliness.

Other options:

A: Echo packets are independent of control packets. Echo may offload failure detection to data plane but does not reduce control packet frequency.

C: Control packet rate is not increased by echo function.

D: Both control and echo packets play roles; it’s not " only control packets " or “only echo packets” used in detection.

Cloud Bursting is the process by which applications or workloads that run in a private cloud or data center environment are " bursted " into a public cloud infrastructure during high-demand periods. This prevents service degradation and ensures performance continuity without manual intervention.

In CCDE design strategy terms, this enables:

Elastic scalability

Cost-effective use of public infrastructure on-demand

Seamless service delivery to end users

Options like “cloud policing” and “cloud shaping” are not standard terms, and “cloud spill” is not an established mechanism. “Cloud bursting” is the correct architectural mechanism that addresses this overflow requirement.

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C: Serialization delay is the time it takes to place a packet onto the physical medium.

E: It is calculated as (packet size / link speed), thus depending on both the packet size and the interface speed.

Why other options are incorrect:

A: It depends on both size and line rate, not just line rate.

B: Packet type has no effect on serialization delay.

D: It ' s not only packet size, but also link speed that affects it.

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