Pass the Cisco CCDE v3.0 400-007 Questions and answers with CertsForce

Ansible is an open-source automation tool that enables configuration management, application deployment, cloud provisioning, and orchestration.

It uses simple YAML-based playbooks and SSH-based connectivity, making it agentless, highly scalable, and easy to integrate with networking environments.

Commonly adopted in network automation, cloud infrastructure provisioning, and service orchestration as part of modern network design practices covered under CCDE v3.1.

Why other options are incorrect:

B (Contrail): Network virtualization platform, not primarily an automation tool.

C (Java): General-purpose programming language, not specifically designed for infrastructure automation.

D (Jinja2): Templating engine, used inside Ansible but not an automation tool by itself.

—

Low-Latency Queuing (LLQ) offers strict priority queuing to real-time traffic (voice/video), ensuring minimal delay, jitter, and packet loss.

This satisfies real-time application requirements which are extremely sensitive to delay variation.

Why other options are incorrect:

A: WFQ offers fairness but no strict prioritization.

B: WRED avoids congestion but is not suited for real-time traffic.

D: FIFO provides no QoS differentiation.

—

Hot-potato routing refers to the practice of routing traffic out of the network as quickly as possible—typically using the shortest IGP path to the egress point. While efficient for internal networks, it can lead to unpredictable routing behavior and suboptimal traffic paths if not coordinated with external peers.

D is correct: Without alignment between internal metrics and external relationships, hot-potato routing can result in asymmetric routing, congestion, or routing loops.

A is incorrect: Content providers often prefer cold-potato routing to control quality of service.

B describes cold-potato routing, where traffic is retained longer.

C is misleading; OSPF doesn’t define hot-potato behavior explicitly—it results from equal-cost metrics and shortest IGP paths.

Unicast Reverse Path Forwarding (uRPF)is a security feature that helps mitigate IP spoofing attacks. It checks whether the source of a packet received on an interface matches the best return path to that source in the routing table.

Strict Mode (C):Ensures the source IP address of a packet is reachable via the same interface on which the packet was received. This prevents forged source IP addresses from traversing the network, which is essential in defending against outbound DDoS attacks sourced from infected hosts.

Loose Mode (B):Only verifies that the source IP exists in the routing table (less strict), which might still allow spoofing in multi-homed or asymmetric environments.

uRPF strict mode is the best fit in secure environments with symmetric routing—commonly in enterprise edge or distribution layers.

==========

Inbound traffic engineering is best controlled by manipulating how external ASes view your routes.

AS path prepending on the 91.7.0.0/16 prefix towards AS 200 makes AS 500 prefer the less-prepended path through AS 100.

This allows granular inbound control for that specific prefix while leaving the rest of the traffic unchanged.

Why other options are incorrect:

B: Extended community is not used for direct inbound path manipulation.

C: Local preference affects outbound traffic, not inbound path selection by remote ASes.

D: MED is only compared between the same AS; it won't affect AS 500's choice.

—

????QUESTION NO: 374 [Business-Driven Design Approaches]

Organic growth or decline affects network demands over time. Which tool helps in designing and operationalizing networks under changing conditions?

A. Change management

B. Modularity

C. Mobility

D. Monitoring

Answer: B

????Explanation:

B: Modularity is a core principle of scalable network design. It allows the network to grow or shrink in response to organic changes in business demand, supporting agility, easier management, and minimal disruption during change.

Other options:

A: Change management is about documenting and approving changes—not a design principle.

C: Mobility refers to user/device flexibility, not structural adaptability.

D: Monitoring detects changes but doesn’t help design the network.

==========

???? QUESTION NO: 375 [Protocol Design Implications]

Company XYZ uses OSPF over redundant paths. What effect does BFD have during a link failure?

A. It would drop the dead peer detection time to a single hello

B. It would keep an alternate path ready in case of a link failure

C. It would optimize the route summarization feature of OSPF

D. It would detect that the neighbor is down in a subsecond manner

Answer: D

????Explanation:

D: BFD (Bidirectional Forwarding Detection) provides subsecond failure detection that is significantly faster than standard OSPF dead timers. When integrated with OSPF, it enables rapid neighbor failure detection, thus speeding up convergence.

Other options:

A: “Single hello” is not a valid BFD metric.

B: BFD does not influence path availability—it only detects failures quickly.

C: BFD doesn’t interact with summarization.

????QUESTION NO: 376 [Security, Automation, and Policy Integration in Design]

What two elements are critical for security and compliance in hybrid cloud environments? (Choose two)

A. Cloud integration and data security

B. Tighter controls based on dynamic policy enforcement

C. Security event and data interoperability

D. Flexible controls based on policy application

E. Orchestration and cross-cloud access security

Answer: C, E

????Explanation:

C: Security event and data interoperability ensures that logs, alerts, and policies can be analyzed across different platforms (private and public clouds), which is vital for compliance and response.

E: Hybrid clouds require secure orchestration across multiple cloud domains, including federated identity, access control, and monitoring across cloud boundaries.

Other options:

A: Too broad; integration is not specific to security/compliance.

B and D: These relate to policy enforcement but don’t directly address interoperability or compliance across multiple clouds.

==========

???? QUESTION NO: 377 [Security, Automation, and Policy Integration in Design]

To protect against future perimeter breaches, which two design options can help? (Choose two)

A. Microzoning

B. Segmentation

C. Domain fencing

D. Virtualization

E. Microperimeters

Answer: B, E

????Explanation:

B: Segmentation isolates network zones (e.g., separating finance from guest access), limiting lateral movement after a breach.

E: Microperimeters apply security controls closer to the application or workload, providing granular control and defense in depth.

Other options:

A: Microzoning is not a widely defined or standard practice in network security.

C: Domain fencing is not a standard security term or methodology.

D: Virtualization is a technology, not a security architecture.

????QUESTION NO: 378 [Network Architecture Principles]

A customer is migrating from a traditional Layer 2 data center to a VXLAN spine-leaf SDN architecture. Applications cannot be readdressed, and migration must occur incrementally. How should the legacy and new networks be connected?

A. via Layer 3 links to border leaf switches

B. via a Layer 2 trunk and Layer 3 routed links to border leaf switches

C. via a Layer 2 trunk and Layer 3 routed links to spine switches

D. via a Layer 2 trunk to border leaf switches

Answer: D

????Explanation:

D: A Layer 2 trunk to the border leaf allows seamless VLAN extension between the legacy Layer 2 domain and the VXLAN-based fabric. This supports application migration without readdressing. Border leaf switches are used to bridge the traditional and VXLAN segments while maintaining MAC learning and VLAN consistency.

Incorrect Options:

A & B: Layer 3 links alone would require readdressing or routing, violating the constraint.

C: Spine switches typically do not handle VLAN bridging or policy enforcement directly.

==========

???? QUESTION NO: 379 [Business-Driven Design Approaches]

Scrum and Kanban are Agile methodologies. In which two scenarios is Kanban more appropriate? (Choose two)

A. acquisition of automation tools

B. carrier lead times

C. network configuration design

D. physical hardware deployment

E. logical topology deployment

Answer: B, D

????Explanation:

B: Kanban is suited for environments with variable lead times, such as carrier provisioning, where tasks arrive irregularly and are processed continuously.

D: Physical hardware deployment is dependent on availability and external logistics—Kanban helps manage such workflows where task durations are less predictable.

Incorrect Options:

A: Tool acquisition is typically a one-off project rather than a workflow suited for Kanban.

C & E: These are better suited for Scrum when planning sprints and structured deployments.

==========

???? QUESTION NO: 380 [Security, Automation, and Policy Integration in Design]

The network has high CPU usage due to excessive inbound traffic impacting the control and management planes. What should be implemented?

A. control plane policing

B. deep interface buffers

C. TCAM carving

D. modular QoS

Answer: A

????Explanation:

A: Control Plane Policing (CoPP) protects the control plane by rate-limiting or dropping unnecessary or malicious traffic destined for the CPU. This is essential in preventing routing and management plane starvation under high traffic conditions.

Incorrect Options:

B: Deep buffers help in data plane congestion, not control plane CPU usage.

C: TCAM carving relates to hardware forwarding table allocations, not CPU protection.

D: Modular QoS is valuable for traffic shaping but not specific to control plane protection.

A: On most hardware platforms, control plane protection is implemented in hardware to safeguard CPU resources from overload due to excessive control traffic.

E: Control plane policing must be carefully sized to allow sufficient protocol traffic (OSPF, BGP, etc.) during normal and convergence periods to ensure stability.

Why other options are incorrect:

B: Policing should be applied universally, not just on external interfaces.

C: False alarms are operational issues but not design considerations.

D: Control plane policers are applied after forwarding decisions for traffic destined to the router CPU.

—

FCoE (Fibre Channel over Ethernet) requires a lossless Ethernet transport, typically achieved using Data Center Bridging (DCB) features such as Priority Flow Control (PFC). Only technologies that can preserve Ethernet frames end-to-end and support lossless characteristics can properly carry FCoE:

A. DWDM (Dense Wavelength Division Multiplexing): Operates at the physical layer and is transparent to Ethernet, preserving frame integrity and lossless characteristics across long distances.

B. EoMPLS (Ethernet over MPLS): Carries Ethernet frames directly over MPLS and can be engineered to support low-loss, low-latency transport appropriate for FCoE.

Why other options are incorrect:

C. SONET/SDH encapsulates Ethernet but is not suitable for FCoE due to differences in timing and buffering.

D. Multichassis EtherChannel over pseudowire may introduce additional control plane complexity and loss characteristics.

E. VPLS introduces MAC learning, flooding, and buffering behaviors that can cause frame loss, which is not compatible with FCoE requirements.

—

B (Enable phone VPN authentication based on end-user username and password):When legacy devices don’t support certificate-based authentication, fallback to username/password provides a temporary workaround while maintaining PCI compliance, assuming strong credentials and secure tunnels are used.

Other options explained:

A: Immediate hardware replacement may not be feasible.

C: TLS 1.0 fallback violates PCI standards, which prohibit deprecated protocols.

D: Clear text authentication is non-compliant with PCI requirements.

—