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

For EIGRP to maintain loop-free alternate paths, the feasibility condition must be met:

A. The Reported Distance (RD) must be lower than the router's Feasible Distance (FD).

E. A feasible successor must exist (i.e., an alternate next-hop satisfying the feasibility condition).

This design allows immediate failover without recomputation, ensuring fast convergence — a critical CCDE v3.1 protocol design principle.

Why other options are incorrect:

B, C, D: Misstate the feasibility condition or confuse RD and FD relationships.

—

A (Encryption + strong authentication) aligns most closely with Zero Trust’s emphasis on always verifying identity and protecting data as it moves across untrusted networks.

Data-in-motion encryption ensures confidentiality, and two-factor authentication ensures strict identity verification.

Why other options are incorrect:

B: Data-at-rest encryption is important but not as critical as controlling data in motion for Zero Trust.

C: Categorization helps in segmentation but is not the core Zero Trust principle.

D: High availability is a design requirement, not the primary Zero Trust security control.

—

In data center migration scenarios, when legacy and VXLAN EVPN networks are connected for host mobility, a critical step is to ensure a seamless Layer 3 gateway handoff. This is typically achieved using VRRP (or HSRP) where both the old and new gateways share the same virtual IP.

The final step involves:

Increasing the VRRP priority on the new VXLAN-enabled infrastructure to make it the active default gateway.

Ensuring that hosts retain their original default gateway (no reconfiguration required).

Only after the new gateway is active, the legacy SVIs can be gracefully shut down.

This method ensures no packet loss or disruption to host connectivity during or after migration.

It aligns with CCDE v3.1 under the “Network Architecture Principles” domain, particularly for data center transformation, operational consistency, and seamless L2–L3 handoff design patterns.

The goal is to prevent AS 111 from being used as a transit AS.

The most effective method is to use an AS path access list to filter outbound BGP advertisements, allowing only prefixes originated from AS 111 (AS path contains only AS 111).

This ensures AS 111 only advertises its own prefixes and does not forward third-party prefixes between providers.

Why other options are incorrect:

A: AS-set is used for aggregation, not for transit prevention.

B: Local preference controls outbound path selection, not advertisement or transit.

D: Prefix list on inbound filters received prefixes, but does not prevent transit.

—

B (Strong cryptography for cardholder data):PCI DSS requires strong cryptographic protocols (e.g. TLS 1.2 or higher) to protect sensitive data during processing and storage.

C (Strong encryption for transmission):Data-in-transit across public or untrusted networks must be encrypted using strong protocols to comply with PCI DSS.

Other options explained:

A/D/E: These are general security best practices but not directly tied to TLS upgrade compliance for cardholder data under PCI DSS.

A (Additional host routes):Spoke-to-spoke dynamic tunnels in DMVPN phase 3 result in OSPF populating routing tables with multiple /32 host routes for each spoke-to-spoke tunnel, which can impact scalability and routing table size.

Other options explained:

B: Priority changes not typically required.

C: Split-horizon issue is solved in DMVPN phase 3.

D: Spokes dynamically register with the hub; no manual spoke IP configuration needed.

D (Unique Local Addresses — ULA): IPv6 addresses in the FC00::/7 range, used for internal networks only, not routable over the global internet.

Ideal for campus or enterprise networks requiring internal-only addressability while avoiding conflict with global prefixes.

Why other options are incorrect:

A & B: Not valid IPv6 address types.

C: Link-local addresses (FE80::/10) are valid only for single-hop communication and cannot be routed even within the local campus.

—

A (Address family translation):Since the requirement states that IPv4-only devices must be able to communicate with IPv6-only devices, anIPv4-to-IPv6 translation mechanismis necessary. NAT64, DNS64, or protocol translation (address family translation) allows devices on different IP families to communicate without requiring both sides to support both protocols.

Other options explained:

B (Dual stack): Allows both IPv4 and IPv6 to coexist on devices, but it does not solve the problem for IPv4-only or IPv6-only endpoints needing to interoperate.

C (Host-to-host tunneling): Requires both endpoints to support tunneling, which is not feasible for legacy devices.

D (6rd tunneling): Primarily enables rapid IPv6 deployment over IPv4 infrastructure, but does not enable interoperability between IPv4-only and IPv6-only devices.

A (Roaming delay):Voice requires seamless roaming with minimal handoff delay to avoid call drops.

B (Uniform radio coverage):Consistent signal coverage is essential for maintaining voice call quality throughout the facility.

Other options explained:

C: High channel utilization affects capacity but not directly the initial readiness assessment.

D: Latency is important but typically captured during ongoing performance testing, not pre-assessment.

E: TX power changes indicate instability but are not primary readiness criteria.

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.

B (RPVST+ — Rapid Per VLAN Spanning Tree Plus): Provides fast convergence while blocking redundant paths to prevent loops — fail closed behavior under failure scenarios.

C (MST — Multiple Spanning Tree): Provides loop prevention and isolates failures to specific instances (VLANs), maintaining fail closed protection.

Why other options are incorrect:

A: EIGRP is a routing protocol; does not operate at Layer 2 to provide fail-closed loop protection.

D: L2MP (Layer 2 Multipathing) allows multiple active links but requires additional loop prevention mechanisms.

—

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.

==========

Both FabricPath and TRILL are Layer 2 multipath technologies designed to eliminate spanning tree and allow for efficient forwarding across Layer 2 fabrics using routing techniques:

B (FabricPath permits active-active FHRP and TRILL supports anycast gateway):FabricPath (Cisco proprietary) integrates with vPC+ to allow active-active First Hop Redundancy Protocol (FHRP) operation at the access layer. This enables multiple default gateways to operate simultaneously, improving resiliency and utilization.TRILL (IEEE standard) uses anycast gateway functionality natively, where multiple switches share the same IP and MAC address for default gateway, allowing hosts to forward to any available gateway, providing active-active behavior at Layer 3.

Other options explained:

A: Incorrect — both FabricPath and TRILL are based on IS-IS for control plane operations; VXLAN is not part of TRILL.

C: Incorrect — both FabricPath and TRILL support ECMP (Equal Cost Multi-Path) to utilize multiple paths efficiently.

D: Incorrect — both technologies allow active-active forwarding at Layer 2.

This comparison highlights CCDE v3.1 design expertise in data center fabric architectures and control plane technologies.

VDI (Virtual Desktop Infrastructure) solutions are latency-sensitive and require:

Low-latency WAN connectivity

Sufficient and predictable bandwidth

Real-time response to user input and video rendering

The primary success factor for VDI is the performance and responsiveness of the remote session, which relies heavily on network characteristics. WAN resizing may also be needed to meet increased load from centralized sessions.

QoS prioritization (Option B) helps but is not sufficient if latency is too high. Placing VDI servers in branch VLANs or DMZs conflicts with the stated goal of centralization.

This aligns with CCDE principles on performance-driven design and service centralization strategies.

B (Proactive network management):Network optimization involves ongoing monitoring, trend analysis, and proactive maintenance to prevent issues before they impact performance.

D (Network health maintenance):Optimization focuses on ensuring consistent network performance, reducing bottlenecks, and maintaining network integrity through regular health checks and adjustments.

Other options explained:

A: High availability is a design goal but not optimization itself.

C: Redesign suggests a major rearchitecture, not part of ongoing optimization.

E: Requirement identification happens during initial design phases.