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

GLOP addressing is defined in RFC 2770. It assigns globally unique multicast addresses based on an organization ' s ASN by mapping the 16-bit ASN into the middle two octets of the 233.0.0.0/8 address space.

233.0.0.0/8 is specifically reserved for GLOP addressing.

The uniqueness of the address is derived from the assigned ASN.

Why other options are incorrect:

A: 232.0.0.0/8 is SSM address space.

C: 239.0.0.0/8 is for administratively scoped multicast.

D: 224.0.0.0/24 is reserved for local multicast (link-local scope).

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Private cloud architecture provides:

On-demand provisioning and decoupling from hardware

Security controls under enterprise ownership

Strong isolation — comparable to an air-gapped model if fully controlled on-premises or in a dedicated hosted environment

While public or hybrid clouds offer flexibility, they cannot guarantee security parity with air-gapped systems unless significant additional controls are implemented. Private cloud supports containerized architectures and modern DevOps pipelines, while keeping the data plane within enterprise boundaries.

This aligns with CCDE’s cloud design principles — balancing modernization goals with strict compliance and cybersecurity mandates.

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CPPr (Control Plane Protection) allows classification and policing of traffic destined for the control plane at a more granular level than CoPP.

It protects the router from control plane attacks such as reconnaissance scans and DoS targeting interfaces and sub-interfaces.

Why other options are incorrect:

A: MPP protects management plane access, not data/control plane protection.

C: CoPP offers global control plane policing but lacks CPPr’s granularity.

D: DPP is not a standard Cisco security mechanism.

B (Configure VXLAN VNID): Each VLAN being migrated must be mapped to a VXLAN VNID for integration into the EVPN fabric. This allows the legacy VLAN to participate in the VXLAN-based Layer 2 overlay and support host mobility.

Other options explained:

A: Pruning is not directly related to migration activation.

C/D: Type 2 routes (MAC/IP routes) and BGP advertisements happen automatically after proper VNID configuration.

Comprehensive and Detailed Explanation:

Central command and control refers to a unified, centralized security policy and management platform that integrates and coordinates all security components—regardless of physical location or form factor (virtual, physical, cloud). It streamlines operations, reduces overhead, and improves visibility and control.

D is correct because central control simplifies policy enforcement and visibility.

A (threat-centric protection) focuses more on response and defense rather than architecture.

B (integrated actionable intelligence) refers to threat feeds, not central management.

C (distributed enforcement) is an implementation strategy, not a management component.

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The hierarchical LAN design model — access, distribution, core — provides:

Scalability through structured hierarchy (A).

Easier change management and staged deployments since functions are isolated at each layer (E).

CCDE v3.1 emphasizes hierarchy for long-term scalability, manageability, and operational stability.

Why other options are incorrect:

B: Modern data centers favor spine-leaf over traditional hierarchy.

C: The model simplifies rather than complicates.

D: Simplification is not its primary advantage — scalability and modularity are.

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PortFast is a feature that allows access ports to enter the STP forwarding state immediately, without waiting for the usual listening and learning states. This accelerates the connection of end devices like PCs or servers.

A key design benefit is that PortFastdoes not trigger topology changeswhen devices are plugged in or disconnected. This prevents unnecessary STP recalculations and protects core stability.

Correct Statement (A):STP does not consider link transitions on PortFast-enabled ports as topology changes, reducing control-plane overhead.

Other options misrepresent the function of PortFast:

B:PortFast does not disable STP; it bypasses specific STP states.

C/D/E/F:These describe other features like Loop Guard or UDLD, not PortFast.

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A (Evaluate bandwidth utilization and connection quality):Before VoIP deployment, a readiness assessment must include bandwidth analysis, latency, jitter, and packet loss to ensure call quality.

Other options explained:

B: DID lines relate to telephony features but not network readiness.

C: Session table limits are unrelated to VoIP readiness.

D: Anomaly detection is security-related, not core network readiness.

Because asymmetric routing is occurring, strict uRPF (which requires the return path match) would block legitimate traffic. In this scenario, deploying uRPF loose mode is optimal:

Loose mode checks only for the existence of the source IP in the routing table, not the exact interface.

It provides protection against spoofed IP packets even if asymmetric routing occurs.

Why other options are incorrect:

A: Null0 static routes do not prevent spoofed source addresses.

B: Strict mode would incorrectly drop valid traffic due to asymmetry.

C: ACLs could help but may not scale or adapt dynamically to traffic patterns.

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To achieve subsecond convergence in IS-IS or OSPF networks and quickly detect both:

Link-layer failures (e.g., interface flaps)

Control-plane adjacency loss

The best solution is:

C. BFD (Bidirectional Forwarding Detection): A lightweight protocol that enables subsecond failure detection, independent of the IGP timers, by establishing fast detection sessions over forwarding paths.

This is widely deployed in high-performance networks to accelerate convergence without compromising routing stability.

Why other options fall short:

A. Debounce timers delay interface-down events (not suitable when fast detection is required).

B. Fast hellos affect hello interval but are still slower and CPU-intensive.

D. LSP fast flood improves LSP propagation but doesn’t address failure detection speed.

This solution is central to CCDE “Protocol Design Implications” where rapid failure detection and recovery drive the convergence architecture.

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A (BPDU Guard on access ports): Prevents accidental connection of switches or bridging devices on access ports, which could cause unexpected topology changes or loops.

C (Root Guard on aggregation switch downlinks): Ensures access switches cannot send superior BPDUs to challenge aggregation switch root status, maintaining predictable STP root placement.

Why other options are incorrect:

B: Aggregation downlinks are not normally configured with BPDU Guard (since they expect BPDUs from access switches).

D: Root guard on access ports is unnecessary as those ports should not participate in STP.

E: Edge port (Rapid STP concept) is good for faster convergence but doesn ' t address stability.

F: STP root and backup root election is important but not a specific STP feature — this is a design decision, not a stability feature.

Software-defined network segmentation is a core element of secure cloud architecture models.

It isolates workloads, minimizes blast radius, and enforces east-west security controls in dynamic multi-tenant environments.

Why other options are less appropriate:

A: This is a principle of least privilege (IAM) but not a cloud architecture characteristic.

B: Dedicated workstations are endpoint measures, not architecture-level.

C: MFA protects identity but does not define architecture segmentation.

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