DevNet Associate (DEVASC) v1.0Understanding and Using APIsEasy

A network operations team is developing an automation script to provision VLANs on multiple Cisco switches using a REST API. The script needs to create a new VLAN by sending a POST request to a `/vlan` endpoint with a JSON payload containing the VLAN ID and name. Which `Content-Type` header value should be included in the HTTP request to correctly inform the API about the payload format?

  1. Amultipart/form-data
  2. Bapplication/x-www-form-urlencoded
  3. Ctext/plain
  4. Dapplication/json
Show answer & explanation

Correct answer: D. application/json

When sending a JSON payload in an HTTP request body, the `Content-Type` header must be set to `application/json` to inform the server that the body contains JSON data. This allows the server to correctly parse the incoming data.

Why the other options are wrong

  • A. `multipart/form-data` is used for sending large binary data or multiple parts, like file uploads.
  • B. `application/x-www-form-urlencoded` is for form data, typically key-value pairs encoded in the URL or body.
  • C. `text/plain` is for unformatted text, not structured JSON data.

HTTP Content-Type Header

An HTTP header that indicates the media type of the resource in the request or response body, specifying how the content should be parsed or interpreted.

  • Crucial for correct interpretation of data exchanged between client and server.
  • Examples include `application/json`, `text/html`, `image/jpeg`.
  • Used in both request (for body sent to server) and response (for body sent to client).

Memory trick: Label your package (data) so the post office (server) knows how to handle it.

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