Cisco Updated 400-007 Exam Questions and Answers by rachel

DTLS (Datagram Transport Layer Security) is the most optimized overlay protocol for SDWAN deployments over public internet, especially when NAT traversal is required.

It combines security similar to TLS while using UDP, which handles packet loss, jitter, and reordering better than TCP-based TLS.

DTLS is natively supported in most SDWAN solutions for encrypted transport across NAT environments without complex configurations.

It allows optimal performance on unreliable or high-latency networks while maintaining strong security standards.

Why other options are incorrect:

A (TLS): Uses TCP, less suited for networks with packet loss or reordering.

C (IPsec): Requires additional NAT traversal mechanisms like NAT-T and may not handle unreliable underlay as effectively as DTLS.

D (GRE): Tunneling protocol without native encryption.

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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.

Encrypting data at rest and in transit is a fundamental best practice to ensure end-to-end data security.

It protects sensitive data both while stored (disk, database) and while moving across networks.

Why other options are incorrect:

A: IPsec secures specific tunnels, but isn’t a complete private cloud solution.

C: Vendor consistency doesn’t guarantee best practice.

D: Anonymization supports privacy but is not a core security best practice for data security.

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B (Separation of infrastructure and policy):SD-WAN decouples policy control from the underlying transport.

C (Simpler policy-based forwarding):Centralized controllers dynamically steer traffic according to application policies with less complexity than traditional QoS in MPLS.

Other options explained:

A: FEC (Forward Error Correction) is typically not used in standard SD-WAN implementations.

D: SD-WAN does not unify WAN backbones; it abstracts multiple underlays.

E: Both MPLS and SD-WAN have failure management, but SD-WAN focuses more on dynamic path control than simply backup links.