300-420 Exam Dumps : Designing Cisco Enterprise Networks

NETCONF supports XML, while RESTCONF supports both XML and JSON. Cisco programmability documentation describes NETCONF as an XML-based protocol that exchanges RPC requests and replies such as get, get-config, and edit-config using XML encoding. NETCONF is tightly aligned with YANG-modeled data, but the protocol message format itself is XML. RESTCONF exposes YANG-modeled data through an HTTP or HTTPS API and can represent payloads in XML or JSON. Cisco DevNet material commonly summarizes the comparison as NETCONF equals XML, while RESTCONF equals XML or JSON. That is why option D is accurate. Option A is wrong because NETCONF does not use JSON in the same way RESTCONF does. Option B is incomplete because RESTCONF is not limited to JSON. Option C reverses the protocol encodings. This distinction matters in automation design because tool selection, content type, parsing, and API workflows differ by protocol. Reference topics: NETCONF, RESTCONF, YANG, XML encoding, JSON encoding, model-driven programmability.

The correct XML/YANG data model set is the option that accurately represents the IOS XE interface hierarchy, assigns the IPv4 address to GigabitEthernet2/1/0, and uses the correct prefix length of 27. In model-driven programmability, the payload must match both the selected YANG model schema and the target platform’s interface naming conventions. For IOS XE native models, interface configuration is structured under the Cisco native namespace, with interface type and name represented in the schema before IPv4 address elements are applied. The address 10.10.10.10/27 must also support a directly connected host at 10.10.10.1/27, which places both addresses in the same 10.10.10.0/27 subnet. Options that place the address under the wrong interface type, use the wrong namespace, incorrectly represent the mask, or configure the host route rather than the interface are invalid. Option D is the only answer aligned to the IOS XE YANG structure and the requested addressing. Reference topics: IOS XE native YANG, NETCONF XML payloads, interface configuration, IPv4 prefix length, model-driven programmability.

DiffServ is the correct scalable QoS architecture for classifying traffic according to business requirements and using DSCP values as the priority descriptor. Cisco QoS design distinguishes DiffServ from IntServ. IntServ uses per-flow signaling with RSVP and can reserve resources, but that model is not operationally scalable across large enterprise networks. DiffServ is class-based. Traffic is classified and marked at the network edge, then each device applies per-hop behavior to those classes using local QoS policy. DSCP provides a six-bit field in the IP header, which supports more than ten classification values and allows standardized treatment classes such as EF, AF, class selector, and default. Best effort provides no differentiated treatment, and RSVP is a signaling mechanism associated with IntServ rather than the requested scalable class-based architecture. “Interserv” is not the correct Cisco QoS model term. Therefore, the engineer should design around DiffServ, with a clear trust boundary, marking policy, queuing model, and consistent treatment across WAN and campus boundaries. Reference topics: DiffServ, DSCP, per-hop behavior, class-based QoS, scalable QoS architecture.