REST APIs & HTTP Practice Questions

Answers and explanations appear when you work through the set above.

1. Which HTTP verb is considered idempotent and is used to completely replace or create a target resource at a specific URI?

   • POST
   • PUT
   • PATCH
   • DELETE

2. When authenticating to Cisco DNA Center REST APIs, which HTTP header must be included in subsequent requests after obtaining an authentication token?

   • Authorization: Bearer <token>
   • X-Auth-Token: <token>
   • Cookie: session_id=<token>
   • API-Key: <token>

3. An API request returns the HTTP Status Code 401 Unauthorized. What does this indicate?

   • The requested resource URL does not exist on the server.
   • The request was successful and a new resource was created.
   • Authentication is missing, invalid, or expired.
   • The server encountered an internal unhandled exception.

4. What is the default validity duration of an authentication token generated by the Cisco DNA Center /dna/system/api/v1/auth/token endpoint?

   • 15 minutes
   • 1 hour
   • 6 hours
   • 24 hours

5. Which syntax formatting rule is strictly enforced in valid JSON data structures?

   • Single quotes (') must be used for string values.
   • Key names must be enclosed in double quotes (").
   • Comments are allowed using // or /* */.
   • Trailing commas are mandatory after the final item in an array.

6. What HTTP status code returned by a REST API server indicates that a resource creation request submitted via POST was processed successfully?

   • 200 OK
   • 201 Created
   • 204 No Content
   • 400 Bad Request

7. Which HTTP method is designed to perform an in-place partial update to a resource without replacing the entire existing object payload?

   • OPTIONS
   • POST
   • PUT
   • PATCH

8. When authenticating to Cisco DNA Center REST APIs, what credentials must be sent to /dna/system/api/v1/auth/token to receive an X-Auth-Token?

   • An OAuth 2.0 Bearer token from an identity provider
   • HTTP Basic auth (Base64 of username:password)
   • A TLS client certificate presented during the handshake
   • An API key passed as a URL query string parameter

9. Which statement accurately describes valid syntax formatting rules within a JSON document?

   • Keys must be wrapped in single quotes, and each key is separated from its value by an equals sign.
   • Keys must be double-quoted strings, and each key is separated from its value by a colon.
   • Nested objects must be indented with tab characters, and every line must end with a semicolon.
   • Comments may be added with a # symbol, as long as they appear on their own line above a key.

10. What is a primary operational advantage of using Webhooks over periodic REST API Polling for event notification?

    • The device must expose privileged CLI access so the receiver can pull the event data directly.
    • Events are pushed to a callback URL as they happen, so the client no longer has to poll.
    • Webhooks skip TLS encryption, so each event payload is smaller than an equivalent REST response.
    • Webhooks run over serial console connections, so they keep working when the network is down.

11. Which of the following examples represents valid JSON formatting syntax for key-value assignments?

    • { 'hostname': 'Core-Router', 'vlan': 10 }
    • { "hostname": "Core-Router", "vlan": 10 }
    • { hostname: "Core-Router"; vlan: 10 }
    • { "hostname": "Core-Router", "vlan": 10, }

12. What HTTP status code is returned by Cisco Catalyst Center when an API request fails due to missing or invalid authentication token credentials in the request header?

    • 200 OK
    • 401 Unauthorized
    • 404 Not Found
    • 500 Internal Server Error

13. In block-style YAML (the style used in Ansible playbooks), which formatting feature represents nested hierarchies and data scope?

    • Curly braces {} surrounding every nested block of keys
    • Space indentation (no tabs used for indenting)
    • A semicolon at the end of every line in a nested block
    • XML angle brackets <> around each parent element name