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

B (OTV — Overlay Transport Virtualization): Allows Layer 2 extension across data centers while maintaining fault isolation by not extending STP across the WAN. Control plane handles MAC learning, which provides stability and loop avoidance between data centers.

Why other options are incorrect:

A: FabricPath is mainly for intra-data center Layer 2 fabric.

C: Advanced VPLS extends Layer 2 but carries STP across the WAN.

D: LISP operates at Layer 3, not for Layer 2 extension.

E: TRILL also focuses on intra-DC Layer 2 but not DCI fault isolation.

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B (EAP - Extensible Authentication Protocol):EAP is commonly used for 802.1X port-based authentication, allowing identity-based control for users on the network. This enables policy enforcement, identity-based segmentation (micro/macro segmentation), and leverages existing domain credentials via backend integration.

Other options explained:

A: LDAP is backend directory, not an authentication protocol for access ports.

C: TACACS+ is used primarily for administrative access.

D: RADIUS transports the EAP exchange but is not the authentication protocol itself.

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.

Comprehensive and Detailed Explanation:

CAPEX (Capital Expenditures) focuses on up-front hardware investments, like routers, switches, and appliances.

A: Scalability directly impacts CAPEX—network designs that require fewer or more scalable hardware components reduce capital investment costs.

B and D are more influenced by OPEX (operational expenditures).

C (complexity) is a broader design challenge, not directly tied to CAPEX.

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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.

D (EoMPLS - Ethernet over MPLS):EoMPLS allows Layer 2 extension across MPLS without IP addressing or routing changes, preserving VLANs and broadcast domains — ideal for extending CCTV networks transparently.

Other options explained:

A: GRE encapsulates Layer 3, requiring IP configurations.

B: L2TPv3 is possible but not common over MPLS SP networks.

C: VXLAN is more suited for data center overlays, not WAN/MPLS integration.

OSPF throttling timers control the pacing and frequency of SPF calculations and LSA generation. They help strike a balance between fast convergence and control-plane stability. The key timers include:

LSA generation throttling (min/max interval between LSA originations)

SPF calculation throttling (delays between consecutive SPF runs)

By tuning these timers, network designers can:

Prevent CPU overload caused by rapid or repeated LSA updates due to flapping links

Smooth out instability while still enabling responsive convergence

This approach aligns with CCDE v3.1 under “Protocol Design Implications” for optimizing IGP behavior in large, dynamic topologies.

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