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

D: CWDM (Coarse Wavelength Division Multiplexing) shares parts of the same optical transmission window (1260–1625 nm) as DWDM but uses wider spacing between channels (typically 20 nm apart).

E: CWDM typically uses passive devices (multiplexers and demultiplexers) that require no electrical power, making deployment cost-effective.

Incorrect Options:

A: CWDM is better suited for shorter distances (up to ~80 km) and doesn ' t typically use optical amplifiers (EDFA). DWDM is better for long-haul with amplification.

B: 850 nm is used in multimode fiber systems (not CWDM).

C: CWDM supports up to 18 channels; DWDM supports up to 32 or more.

==========

C (More consistent device configuration):Centralized control allows uniform policy application, eliminating configuration drift across devices.

E (Configure features at network-level rather than device-level):Controller-based networks abstract network services from individual devices, enabling network-wide configuration from a single source of truth.

Other options explained:

A: Forwarding tables still exist in both architectures.

B: Traditional networks offer per-device flexibility; controllers abstract this.

D: APIs are usually provided at controller level, not per device.

B (IPFIX telemetry data):IPFIX provides detailed flow-level visibility, enabling identification of traffic patterns, data flows, and destinations. This data is critical for understanding current traffic behavior to identify governance gaps and improve policy compliance.

Other options explained:

A: Secure tunnels protect traffic but do not identify governance gaps.

C: Firewalls provide limited flow visibility compared to telemetry.

D: Workload policies enforce security but do not aid initial visibility analysis.

C (PIM Sparse Mode with RP located at the hub):DMVPN networks typically leverage sparse mode multicast due to their efficiency in dynamic topologies. Locating the Rendezvous Point (RP) at the hub simplifies multicast state management, since the hub serves as the central aggregation point and ensures optimal rendezvous functionality without requiring complex RP placement across spokes.

Other options explained:

A: Dense mode is inefficient and generates unnecessary flooding, especially in WAN environments.

B/D: Placing RPs at remote sites introduces unnecessary complexity and operational challenges.

When logical VRF separation is based on fields like IP address ranges or packet characteristics (such as packet length), the most scalable solution is:

Policy-Based Routing (PBR): This allows traffic to be classified and forwarded into the correct VRF based on flexible match conditions like source IP address, destination IP address, or packet size.

Why other options are incorrect:

A: Static route leaking lacks flexibility and scalability for dynamic classification.

C: OSPF per VRF handles control-plane separation, but not data-plane traffic classification.

D: MP-BGP is used for control-plane VPN route exchange, but not for VRF selection based on traffic attributes.

—

SDN controller — Maintains a complete view of everything that is happening in the network; Manifested as either a physical or virtual component

Southbound interface — Communicates with network devices to program the data plane; Provides access to the network to configure or to retrieve information from it

Northbound interface — Exposes access to the controller; Characterized as a software interface