400-007 Exam Dumps - Cisco Certified Design Expert (CCDE v3.1)

Comprehensive and Detailed Explanation:

A: QoS (Quality of Service) helps preserve performance for critical applications when only one link is available by prioritizing high-value traffic. This solution works within existing infrastructure—meeting the "no additional CAPEX" requirement.

Other options:

B and C introduce new hardware or services—thus increase CAPEX.

D: Dynamic routing helps with failover but doesn't solve the bandwidth issue under failure conditions; QoS does.

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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.

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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.

A (Access):QoS classification and marking should occur as close to the traffic source as possible—at the access layer—so that policies can be consistently applied throughout the network.

Other options explained:

B/D: QoS policies at these layers rely on markings applied earlier.

C: Collapsed core is simply core and distribution merged, but marking should still happen at access.

In most Cisco NAT implementations:

Local-to-global NAT translations occur before policy-based routing (PBR), meaning that NAT happens first, and then PBR decisions are made based on the translated addresses.

This sequence is important when designing overlapping address spaces, as NAT must be applied before routing policies can correctly forward traffic based on global addresses.

Other options explained:

A: Incorrect sequence.

B/D: Global-to-local translations occur during inbound processing but not in the order described relative to PBR.

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