200-901 Exam Dumps - DevNet Associate (DEVASC)

YANG (Yet Another Next Generation) is a data modeling language used to model configuration and state data manipulated by the NETCONF protocol. Here are two advantages of YANG-based approaches for infrastructure automation:

Multi-platform vendor abstraction (Option B):

YANG provides a standardized way to model configuration and state data, enabling multi-platform vendor abstraction. This means that network engineers can write configurations and management scripts that work across different network devices from different vendors, as long as they adhere to the YANG model. This reduces the complexity and increases the interoperability in multi-vendor environments.

Designed to reflect networking concepts (Option C):

YANG is specifically designed to reflect networking concepts and constructs, making it intuitive and effective for defining network configurations and states. The hierarchical structure of YANG models aligns well with the structure of network configurations, allowing for precise and clear definitions of network elements and their relationships.

References:

Cisco YANG Overview

IETF YANG

When a developer is writing an application that interacts with a REST API, the status code of the response is a critical element used in conditional checks. The status code provides information about the success or failure of the request. Common status codes include:

200: OK (The request was successful).

201: Created (The resource was successfully created).

400: Bad Request (The server could not understand the request due to invalid syntax).

401: Unauthorized (Authentication is required and has failed or has not been provided).

404: Not Found (The requested resource could not be found).

By checking the status code, the application can determine if the request was successful and handle errors appropriately.

When authenticating a RESTCONF API session with a router running Cisco IOS XE software, basic authentication is commonly used. Basic authentication involves sending the username and password in the HTTP header encoded in base64 format. This method is straightforward and widely supported, though it is less secure compared to token-based authentication and should be used with HTTPS to ensure the credentials are encrypted in transit.

When consuming a RESTful API that returns large amounts of data, pagination is commonly used to divide the data into manageable chunks. Pagination helps reduce the load on the server and the client by providing only a subset of the total data in each response. The client can request the next set of data using parameters such as page or limit.

1 – E, 2 – B, 3 – D, 4 – A

gRPC = C, NETCONF = A, RESTCONF = B, D

OR

The CNAME (Canonical Name) record is used in DNS to create an alias that points to another domain name. This domain name then resolves to an IP address. For instance, if you have a CNAME record for www.example.com pointing to example.com, accessing www.example.com will direct you to example.com, which will ultimately resolve to the IP address of example.com. This is particularly useful for pointing multiple domain names to the same IP address, allowing easier maintenance and updates. References for this can be found in Cisco's DNS documentation.