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

B (Minimize operational costs): A common business goal to reduce long-term operating expenses.

E (Reduce complexity): Simplifying designs reduces operational overhead, risk, and failure domains.

Why other options are incorrect:

A: Resiliency is a design goal, but not a business objective itself.

C: Endpoint posture is a technical security feature.

D: Faster obsolescence contradicts business optimization.

In MPLS networks, the MPLS header contains a 3-bit EXP (experimental) field that is used for QoS classification. Since the customer edge (CE) is managed by the service provider, it is common and best practice to map customer traffic classification (DSCP) into MPLS EXP at ingress into the MPLS core. This allows consistent QoS treatment throughout the core.

DSCP provides granular QoS markings (6-bit field, 64 values) which can be easily mapped to 3-bit EXP (8 values).

Mapping DSCP to EXP supports the 6-class model required by many service providers.

Why other options are incorrect:

A, C: IP CoS and IP precedence are legacy and not as granular as DSCP.

B: Flow-label is used in IPv6 for traffic engineering, not for MPLS QoS classification.

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When a service provider does not support multicast over their Layer 3 VPN, the enterprise can useGRE tunnels between Customer Edge (CE) devicesto transport multicast traffic. This method allows the customer to encapsulate multicast packets in unicast GRE packets, which are routable through the provider’s non-multicast core.

In this scenario, the most scalable and immediate solution is to establish a GRE tunnel betweenC2 (in the head office CE router path)andC4 (at the branch office). This setup ensures that multicast traffic originating at the head office is tunneled directly to the multicast receivers, bypassing the service provider’s non-multicast-aware core.

This strategy is directly aligned with CCDE v3.1 principles, which emphasize:

Minimizing service provider dependency

Providing a scalable, customer-controlled overlay solution

Ensuring protocol compatibility across domains

Why other options are incorrect:

A: Tunnel between CE1 and CE2 is less optimal, as it may not originate or terminate at the exact multicast endpoints.

C: Tunnel between C1 and C4 is less aligned with CE-to-CE design expectations and may bypass required edge security/policy controls.

D: 2547oDMVPN is more complex and intended for full-scale VPN overlays, not quick multicast solutions.

E: Draft Rosen requires service provider support, which is currently unavailable, hence not a valid short-term option.

This solution ensures operational simplicity and future scalability with minimal provider dependency, which are core principles outlined in the CCDE v3.1 design methodology.

NETCONF (Network Configuration Protocol) is a standardized protocol used for automating configuration and management of network devices. According to IETF standards (RFC 6241), the required encoding for NETCONF is:

XML (Extensible Markup Language)

Cisco IOS XE supports NETCONF over SSH and uses XML to structure both configuration data and RPC messages. XML allows strict schema validation (via YANG models), extensibility, and rich hierarchical structure required for modern network automation.

Other formats:

HTML is not a data encoding method.

YAML is typically used with configuration management tools, not NETCONF.

JSON is supported in RESTCONF, not in traditional NETCONF.

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C (Untrusted VLAN): In out-of-band NAC Real-IP Gateway mode, unauthenticated clients are placed into the untrusted VLAN. The Clean Access Server handles traffic from these clients until authentication is complete.

Why other options are incorrect:

A: Authentication VLAN applies to some inline modes but not Real-IP Gateway.

B: User VLAN is assigned after successful authentication.

D: Management VLAN is used for administration, not for client onboarding.

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IPv6 multicast supports two key mechanisms for Rendezvous Point (RP) discovery:

A. Embedded RP: The RP address is embedded within the multicast group address (ff70::/12). This allows automatic RP discovery by routers and eliminates the need for signaling protocols.

C. BSR (Bootstrap Router): Used in IPv6 as a replacement for Auto-RP (which is IPv4-specific), BSR dynamically announces the RP to multicast routers in the domain.

Other options:

B. MSDP: Not supported in IPv6 multicast since source registration and discovery are handled differently.

D. Auto-RP: IPv4-specific and not supported in IPv6.

E. MLD: Manages listener (receiver) membership, not RP discovery.

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B (Added redundancy): Redundancy ensures alternate paths or systems are available if a failure occurs, which is the primary design principle behind resiliency. Redundancy directly contributes to higher network availability and fault tolerance.

Why other options are incorrect:

A: Load-balancing optimizes performance but doesn’t inherently improve resiliency.

C: Confidentiality addresses security, not resiliency.

D: Reliability is an outcome, not a design principle itself.

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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.

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In the design ofIPv6 multicast services, particularly usingPIM Sparse Mode, thefirst-hop router(which is connected to the multicast source) must register the multicast source with theRendezvous Point (RP). This registration involves encapsulating the multicast packets in unicast messages and sending them to the RP.

This encapsulation is done over adynamically created tunnel interface, typically referred to as aPIM Register Tunnel. This temporary tunnel is established by the source-side router to send encapsulated multicast traffic to the RP for initial source registration.

Therefore, the dynamic tunnel serves the purpose of:

Encapsulating and sending the first multicast packets from the source to the RP

Allowing the RP to learn about new sources and initiate shared tree or shortest-path tree forwarding

This operation aligns with CCDE v3.1 design principles, where understanding the internal operation of multicast protocols—especially source registration and RP role—is critical for scalable and reliable multicast service delivery.

Why other options are incorrect:

A: First-hop router doesn’t register itself, it registers thesourceto the RP.

B: Clients (receivers) do not register to the RP; they send IGMP/MLD joins which flow toward the RP.

D: Not all IPv6 multicast traffic is transported via tunnels; only initial registration traffic is encapsulated in this manner.

This mechanism is essential for source discovery in sparse-mode multicast and is foundational to multicast tree building in IPv6 networks.

B (Encapsulation at source and destination):Overlay networks encapsulate payloads inside another protocol (e.g. VXLAN, GRE, MPLS), adding headers that enable separation from the underlay network while introducing minor overhead due to encapsulation.

Other options explained:

A: Describes underlay behavior.

C: Overlay encapsulation occurs independently of L3/L4 reliability.

D: NAT or VRF are isolation mechanisms but not how overlays function.

Agile project management supports:

Frequent updates and iterative feedback loops

Flexibility to accommodate evolving requirements

Continuous customer collaboration and transparency

This methodology is ideal for projects where scope may shift and customer involvement is essential. In contrast:

Waterfall is linear and rigid

Phased delivery segments milestones but limits change midstream

“Three principles” is not a recognized methodology in this context

Agile aligns with modern IT deployment models and is supported in CCDE methodology as a business-aligned and adaptive design execution strategy.

Traffic shaping buffers excess traffic and smooths traffic bursts, which is essential for DaaS traffic sensitive to periodic link congestion across WAN circuits.

It helps ensure consistent, predictable performance under fluctuating WAN conditions.

Why other options are incorrect:

A: Tail drop leads to congestion and packet loss.

C: WRED is used for congestion avoidance, but not ideal for real-time DaaS traffic shaping.

D: Policing drops excess traffic instead of buffering, worsening DaaS disconnections.

SD-WAN design principles:

C: Centralized policy, simplified management, and dynamic path selection improve operational efficiency, directly resulting in cost savings.

D: SD-WAN provides centralized orchestration, automation, and zero-touch provisioning, simplifying deployment and scaling.

Why other options are incorrect:

A: SD-WAN improves performance with features like dynamic path selection but cannot inherently prevent slow underlay performance.

B: Many SD-WAN solutions logically separate control and data planes, but not all strictly follow full separation like traditional SDN.

E: SD-WAN is typically hardware-agnostic but does not depend on specialized switching hardware.