300-420 Exam Dumps : Designing Cisco Enterprise Networks

The correct code snippet must use a secure HTTPS-based RESTCONF transaction with the YANG JSON media type. The requirement explicitly states that the content type is application/yang-data+json and that the connection to the network device must be secured. In Cisco IOS XE programmability, RESTCONF uses HTTP methods against YANG-modeled resources, and secure deployments use HTTPS rather than clear-text HTTP. A loopback interface with address 172.16.15.12/32 would be configured by sending a JSON payload that follows the selected YANG model structure, commonly an IETF or Cisco native interface model, with the correct content-type and authentication headers. The key security indicator in the option must therefore be HTTPS/TLS, not an insecure HTTP URL or a non-YANG content type. NETCONF over SSH would also be secure, but the stated content-type points to RESTCONF with JSON encoding. Option A is the valid snippet because it aligns the payload format with a secure transport. Reference topics: RESTCONF, YANG JSON encoding, application/yang-data+json, HTTPS, IOS XE programmability.

A TLOC extension facilitates WAN Edge router redundancy within a site. In Cisco SD-WAN, a Transport Location identifies a WAN transport attachment using attributes such as system IP, color, and encapsulation. A TLOC extension allows one WAN Edge router to use a transport circuit physically connected to another WAN Edge router at the same site. This is valuable when a branch has two edge routers and two transports, but each transport is cabled to only one router. With TLOC extension, each router can still gain logical access to both transports, improving redundancy and allowing better path diversity without adding more service-provider circuits or handoffs. The feature does not simply identify the physical interface; that is part of TLOC definition. It does not increase the number of colors or create a port-channel-style aggregate. A sound design also accounts for failure domains, service-side routing, and whether the inter-router link has enough bandwidth for extended transport traffic. Reference topics: Cisco SD-WAN TLOC, TLOC extension, WAN Edge redundancy, transport color, branch resiliency.

TLOC extension is the Cisco SD-WAN mechanism that allows a WAN Edge router without direct access to a transport to reach that transport through another WAN Edge router at the same site. Cisco describes TLOC extension as a redundancy feature in SD-WAN networks. In the question, the WAN Edge router is connected to an MPLS transport link, but Internet access is available through another WAN Edge device. With TLOC extension, the MPLS-only edge can extend traffic through the peer router toward the Internet transport, allowing the site to use multiple transports without requiring every edge router to have a physical connection to every circuit. OMP can advertise routes and TLOCs, but OMP alone does not create physical Internet access for a router attached only to MPLS. Requiring a local 4G/5G or Internet circuit on the same router is not necessary when TLOC extension is part of the design. An MPLS extranet is also not the normal SD-WAN solution for Internet transport reachability. Therefore, TLOC extension is the correct design method.