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

This scenario describes a centralized control mechanism where:

The SDN controller learns the network topology using BGP Link-State (BGP-LS).

The controller installs control-plane policies using protocols like PCEP or BGP.

Policies are pushed centrally and result in new RIB entries at the routers.

This is the hallmark of a centralized SDN architecture:

The controller has a global view and decision-making logic.

Routers remain relatively simple in the control plane and act on instructions.

This aligns with CCDE v3.1 under the “Technology Comparisons and Use Cases” topic, where SDN models are compared:

Centralized SDN (controller-driven)

Distributed SDN (traditional)

Hybrid (a blend of both, which is not represented here)

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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.

B (Install firewalls):PCI DSS requires network segmentation, filtering, and perimeter defense via firewalls.

C (Use antivirus software):Malware protection and anti-virus software are mandatory on all systems interacting with cardholder data.

Other options explained:

A/D/E: These are general security best practices but not specific mandatory requirements under PCI DSS control objectives.

Inbound traffic engineering is best controlled by manipulating how external ASes view your routes.

AS path prepending on the 91.7.0.0/16 prefix towards AS 200 makes AS 500 prefer the less-prepended path through AS 100.

This allows granular inbound control for that specific prefix while leaving the rest of the traffic unchanged.

Why other options are incorrect:

B: Extended community is not used for direct inbound path manipulation.

C: Local preference affects outbound traffic, not inbound path selection by remote ASes.

D: MED is only compared between the same AS; it won ' t affect AS 500 ' s choice.

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The design requires scalability, centralized credential management, device independence, and role-based access:

B (Central authentication directory): A centralized directory (such as Active Directory, RADIUS, or LDAP) allows the VPN solution to leverage existing user credentials, support role-based access control, and scale easily.

F (SSL VPN): Provides remote access VPN services that support a variety of client devices, including unmanaged or personal devices, without requiring device certificates. SSL VPN is well-suited for scenarios where users may not always use the same device.

Other options explained:

A: Local usernames/passwords do not scale to thousands of users and lack centralized policy control.

C/E: Certificates would require device management and may not be feasible if users switch devices.

D: IPsec VPN can work, but typically requires more complex client configuration and may not support flexible device usage as well as SSL VPN.

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