CCNA Cisco Platforms and Development Questions

Platform APIs include the event notification and webhook services that register subscribers and deliver DNA Center events, such as device-added, to an external endpoint. This satisfies the stem's event-driven requirement, unlike intent, command runner or integration APIs, which handle policy, CLI execution or third-party connectivity rather than push notifications.

HTTP 429 is 'Too Many Requests', returned when the client exceeds the Meraki API's rate limit. The Retry-After header tells the client how long to wait before retrying, confirming the request was throttled rather than rejected for authentication or syntax.

Sending a message to a room is a create operation on the messages collection, so the bot calls POST /v1/messages with the roomId in the JSON body. The room ID alone does not form a resource path for a GET or PUT.

pyang is an open-source YANG validator and converter that parses YANG modules locally, letting engineers inspect tree structures, verify syntax and explore model hierarchies without a live device. It directly satisfies the requirement to explore YANG models offline.

Cisco NX-OS exposes NX-API, which wraps CLI commands and returns structured JSON or XML over HTTP/HTTPS, enabling programmatic access. IOS, IOS-XE and ASA lack this native JSON CLI wrapper, so NX-OS is the platform matching the stem.

The Meraki Dashboard API exposes organisations at GET /organizations under the /api/v1 base URL, and authentication uses the X-Cisco-Meraki-API-Key request header carrying the dashboard API key. This matches the stem's base URL and required listing operation exactly.

The get-config operation retrieves configuration data from a specified datastore, and the source element must name that datastore. Pairing <running/> with a subtree filter that matches the Cisco IOS XE native hostname leaf returns only that fragment instead of the whole running configuration, which is exactly what the scenario requires.

The event syslog pattern detector matches incoming syslog messages against a regular expression, triggering the applet when the specified text appears. This directly satisfies the requirement to react to a specific syslog message rather than a timer or interface event.

Site creation is part of changing the network topology.

The Link header with rel="next" signals cursor-based pagination: the API returns a partial result set plus a URL for the following page. Following that URL directly retrieves the next batch, so the developer iterates until no rel="next" link remains.

Correct. Basic Auth is used to get a token for subsequent API calls.

GET requests to `/dna/intent/api/v1/network-device` return the full device inventory from Cisco DNA Center's intent API, satisfying the requirement to retrieve, not modify, all network devices. The GET method is idempotent and read-only, matching the stem's retrieval constraint without side effects.

POST to /dataservice/template/device creates a new device template in vManage. The request body must include the device model and the template configuration. This matches the requirement to create a device template, and POST is the correct method for resource creation on the vManage REST API.

Correct. Template deployment, plug and play are part of 'change your network'.

Meraki Dashboard authenticates REST calls solely through the `X-Cisco-Meraki-API-Key` request header carrying the generated API key; no OAuth bearer token or session cookie is accepted. This satisfies the stem's requirement for the mandatory authentication header on every Dashboard API call.

To add a member to a Webex space, you send a POST request to /v1/memberships with a JSON body containing 'roomId', 'personEmail', and optionally 'isModerator'. This creates a new membership. The API returns the membership details. This is the correct method and endpoint for adding a member.

Meraki's Dashboard API returns a Retry-After header on 429 responses that indicates how many seconds the client must wait. Honoring this header prevents further throttling and aligns with Meraki's documented rate-limit behavior. Simply pausing for a fixed interval without reading the header may retry too soon or waste time.

Meraki's REST API paginates large collections, returning a Link header containing the URL of the next page of results, often with rel="next". The engineer follows that URL to retrieve subsequent networks until no Link header remains, indicating the final page.

NX-API's JSON-RPC interface accepts commands at the /ins endpoint via HTTP POST, with the CLI commands supplied in the JSON body. GET is unsuitable because it cannot carry the command payload, and /cli returns plain text rather than JSON.

The Meraki Dashboard API authenticates every call with a dedicated request header rather than a query string or bearer token. Supplying the key as X-Cisco-Meraki-API-Key satisfies the stem's requirement for the correct method when issuing GET https://api.meraki.com/api/v1/organizations, keeping credentials out of the URL and logs.

The GET /dna/intent/api/v1/network-device endpoint targets Cisco DNA Center's Intent API, returning the full inventory of managed network devices. Its HTTP GET method and network-device resource path satisfy the requirement to retrieve, not modify, device listings.

Assigning a device to a site is another key operation in Site Management. This is done via endpoints such as POST /dna/intent/api/v1/site/{siteId}/device. It associates a network device with a specific site, enabling site-based monitoring and policy enforcement. This operation is fundamental for site-based management.

endingBefore retrieves items before a given ID, effectively moving backward.

In ncclient, the get_config method retrieves configuration data from a specified datastore. Using source='running' fetches the running configuration. This is the correct method for retrieving configuration via NETCONF. The method returns a response object containing the configuration in XML format, which can then be parsed.

The Rooms API lets the bot enumerate and inspect Webex spaces, supplying the roomId that every message response must target. Without it, the bot cannot determine which conversation to post into, so it satisfies the requirement to respond automatically to messages received across multiple rooms.

Cisco Meraki's cloud-managed dashboard exposes a REST API authenticated with an API key in the request header and enforces a documented rate limit of 5 requests per second per organisation, matching all three stated constraints.

A 404 Not Found indicates that the server cannot find the requested resource. Even with valid IDs, if the endpoint path is wrong (e.g., misspelled 'vlans' or wrong API version) or the specific port does not exist, the server returns 404. The developer should double-check the URL structure and ensure the port identifier is valid for that switch.

The Meraki Dashboard API authenticates each request by placing the API key in the X-Cisco-Meraki-API-Key request header. This satisfies the stem's requirement, since the key is passed as a custom HTTP header rather than a query string or bearer token.

The Webex messages endpoint accepts toPersonEmail to address a recipient directly by their email address. This satisfies the stem's requirement to send a message to a specific person identified by email, rather than by person ID or room ID.

The GET method against /dna/intent/api/v1/network-device queries Cisco DNA Center's Intent API inventory collection, returning the full device list as JSON. This satisfies the stem's requirement to retrieve, rather than modify, network devices, since GET is the read-only HTTP verb mapped to that resource.

Basic Authentication encodes the administrator's credentials and posts them to /dna/system/api/v1/auth/token, which returns a time-limited token. Cisco DNA Center requires this token exchange before any other API call, satisfying the stem's constraint that a token must be obtained first.

GET /v1/people/me returns the authenticated user's own profile, identified by the access token, so no user ID is needed. Other people endpoints require an explicit personId, making them unsuitable for retrieving the current user's information.

The `GET /dna/intent/api/v1/network-device` endpoint retrieves all network devices from Cisco DNA Center, satisfying the stem’s requirement to “retrieve a list” by using the HTTP GET method, which is idempotent and safe for read-only operations. This contrasts with POST, which would create a new resource, and DELETE, which would remove devices. The path’s `/network-device` resource collection directly maps to the requested data set.

Action cli command runs a command.

NX-API REST uses HTTP POST to send configuration commands or JSON payloads. The Content-Type header must be application/json when sending JSON. The body contains the configuration in JSON format, such as the VLAN creation object. This is the standard way to configure via NX-API REST.

The 'feature nxapi' command enables the NX-API feature on a Cisco NX-OS device. This allows the switch to accept HTTP/HTTPS requests for CLI commands and retrieve configuration or operational data. Without this feature enabled, the switch will not respond to NX-API requests. It is the essential first step for using the NX-OS API.

Webhooks push event notifications to a supplied HTTPS endpoint the moment a message is created, satisfying the real-time constraint. Polling the messages resource would introduce latency and unnecessary API calls, so webhooks are the designed mechanism for immediate room activity alerts.

The GET /dna/intent/api/v1/network-device endpoint returns the list of all network devices in the DNA Center inventory. It supports query parameters such as reachabilityStatus and managementState to filter results. This is the correct endpoint for retrieving device inventory information from the Intent API.

A 429 signals rate limiting, and the Meraki Dashboard API returns a Retry-After header giving the exact backoff interval. Honouring that value respects the documented rate-limit window, so the retry succeeds rather than being throttled again. Immediate retries or fixed delays ignore the server-supplied timing and risk further 429 responses.

The "Change your network" category covers configuration and deployment operations, including template deployment to devices via the DNA Center template APIs. This satisfies the stem's requirement for the API category that deploys configuration templates, rather than monitoring or inventory categories.

Embedded Event Manager applets run on the IOS XE device itself, matching syslog patterns via event statements and triggering CLI actions through action statements. This delivers the required local, event-driven automation without external orchestration tooling.

The Intent API's "Change your network" category covers configuration operations, including deploying templates to devices. It satisfies the stem's requirement for programmatic template deployment across multiple devices, unlike monitoring or integration categories that only read data or connect platforms.

Creating a message is a resource-creating operation, so the Webex messaging API expects POST against the /v1/messages collection endpoint, with the roomId and text in the JSON body. GET on that path would only list messages.

The Meraki Dashboard API authenticates every call with a static API key passed in the X-Cisco-Meraki-API-Key request header, satisfying the stem's requirement for the dashboard's native authentication method. Unlike OAuth 2.0 bearer tokens, which Meraki does not issue for dashboard API access, this header-based key is the sole supported credential.

The event cli detector triggers an EEM applet when CLI input matches a specified regular expression, which is exactly the requirement to react to a particular command being entered. Other detectors watch syslog, SNMP, timers or interface counters, none of which fire on command entry.

The candidate datastore exists specifically to stage changes before they take effect. Locking prevents concurrent edits, the validate operation checks the staged configuration, and commit applies it only when validation succeeds. This sequence meets the atomic, validated, non-persistent-on-failure requirement and is the standard ncclient workflow for transactional configuration.

The Meraki Dashboard API uses pagination via the Link header. When more results exist, the Link header includes a rel="next" URL. By following that URL until no next link is provided, the developer can retrieve all networks. This is the correct method to handle pagination in the Meraki API.

HTTP 429 signals the Meraki Dashboard API rate limit has been exceeded. The Retry-After header specifies the number of seconds the client must wait before issuing another request; retrying earlier risks further throttling. This is a throttling response, not an authentication or server error.

Task management belongs to the Platform API category, exposing asynchronous job operations such as checking task status and results. It lets callers track long-running operations initiated through other DNA Center APIs, distinct from Intent or Know Your Network categories.

NX-API is disabled by default on Nexus switches and must be activated with the command 'feature nxapi' in configuration mode. Enabling this feature starts the HTTP/HTTPS listener that accepts JSON-formatted CLI requests, satisfying the stem's prerequisite.

The candidate capability means the device supports a candidate configuration datastore that can be edited, validated, and then committed atomically. Combined with confirmed-commit, this allows the developer to stage changes and have them automatically rolled back if the commit is not confirmed, which is exactly the safe configuration workflow described.

The Cisco DNA Center Intent API provides a GET endpoint at /dna/intent/api/v1/site to retrieve all sites. This endpoint returns a list of sites defined in the network hierarchy. It is a read-only operation that requires authentication via an X-Auth-Token header obtained from the authentication API. This is the correct way to list sites.

The DNA Center intent API exposes Layer 2 topology through the topology/l2 path, and appending the VLAN identifier scopes results to that broadcast domain. Querying this endpoint with GET returns nodes and links for the specified VLAN, matching the requirement.

GET /v1/people/me returns the authenticated user's own profile, resolving the caller's identity from the OAuth token rather than requiring an explicit person ID. This satisfies the stem's requirement to retrieve the current user's Webex profile information without knowing or supplying their identifier in advance.

Cisco DNA Center uses token-based authentication. The developer must send a POST request to the '/dna/system/api/v1/auth/token' endpoint with the username and password encoded in Base64 in the Authorization header. The response contains a token that must be included in subsequent API calls as 'X-Auth-Token'. This is the standard method for DNA Center API authentication.

Creating a message is a resource-creation action, so the Webex messaging API expects an HTTP POST to the /v1/messages collection endpoint. The target room is identified by passing roomId in the JSON request body, which routes the message to that specific room.

DNA Center provides a token endpoint at /dna/system/api/v1/auth/token. The developer sends a POST with Basic Auth credentials to receive a time-limited token, which is then used in the X-Auth-Token header for subsequent API calls. This is the correct token-based method and avoids hardcoding credentials in each request.

GET /v1/people/me returns the authenticated user's own profile, resolving identity directly from the bearer token rather than requiring a person ID. This satisfies the stem's requirement to retrieve the current user's details without first querying another endpoint to discover their identifier.

The Link response header returns RFC 5988 web-linking metadata, including rel="next", rel="prev", rel="first" and rel="last" URLs. This satisfies the stem's pagination constraint: Meraki's API caps results per page, so clients follow the rel="next" URL to retrieve subsequent records until no further link is supplied.

The `event syslog pattern` trigger matches syslog messages against a regular expression, firing the applet when the specified pattern appears in the device log. This directly satisfies the stem's requirement to react to a specific syslog message, unlike timer, interface, or SNMP-based triggers.

The Meraki Dashboard API authenticates requests with a dedicated header named X-Cisco-Meraki-API-Key carrying the organization's key. When that key is missing, revoked, or malformed, the dashboard rejects the call with a 401 Unauthorized status. This matches the scenario's requirement to read the key from an environment variable and place it in the correct header.

Correct. After authenticating and obtaining the token, the GET request to /dna/intent/api/v1/network-device is the step that retrieves the device list. It must include the Bearer token in the Authorization header, which is established in the previous step (option C).

The Webex Teams API uses POST /v1/messages to create a message. The request must include the roomId and text parameters in the JSON body. The access token is passed in the Authorization header as a Bearer token. This is the correct method and endpoint for sending a message to a room.

Webex webhooks subscribe to a resource and event pair. Specifying resource 'messages' with event 'created' fires the webhook whenever a new message is posted in any room the bot belongs to, matching the required trigger scope exactly.

EEM supports timer-based events.

Resource specifies what to monitor.

`startingAfter` accepts the identifier of the last record from the previous page, so the Meraki API returns only records positioned after it. This directly satisfies the stem's requirement to specify the starting point for the next page, unlike `perPage`, which only controls page size.

RESTCONF exposes the native data model at /restconf/data/, and the hostname leaf sits under the Cisco-IOS-XE-native:native container. A GET on that exact path returns the configured hostname, matching the YANG-modelled URL structure IOS XE publishes.

GET /dna/intent/api/v1/network-device targets the Intent API's network-device resource, returning the full device inventory Cisco DNA Center manages. The GET method satisfies the read-only retrieval the engineer requires, and the endpoint path matches the platform's versioned REST structure, so no filtering or configuration change is needed.

Meraki returns HTTP 429 when the rate limit is exceeded, and the Retry-After header specifies how long to pause. Throttling concurrent requests and honouring that value prevents further throttling and aligns the client with the documented limit.

Sending a message creates a new resource in the Webex messaging collection, so the POST method targets /v1/messages with the roomId and text in the JSON body. GET retrieves existing messages, and PUT or DELETE would modify or remove them, not send.

Meraki Dashboard API authenticates requests using a custom header named X-Cisco-Meraki-API-Key whose value is the API key generated in the dashboard. This header must be present on every call, and the script can populate it from the environment variable to avoid hardcoding the secret in source code.

NX-API exposes an /ins endpoint that accepts JSON-RPC or XML requests over HTTPS for CLI-based commands. Sending a POST with the proper JSON body containing the command and parameters is the documented way to retrieve configuration. This endpoint is specifically designed for programmatic access to NX-OS CLI.

The Webex messaging endpoint accepts a POST to /v1/messages, where the JSON body supplies the target 'roomId' and the message content via the 'text' parameter. This pairing delivers a plain-text message to the specified room, matching the developer's simple text-body requirement.

The Cisco DNA Center Intent API provides the /dna/intent/api/v1/network-device endpoint to retrieve the list of devices in the inventory. A GET request to this endpoint returns a JSON array of device objects. This is the standard endpoint for device inventory retrieval in DNA Center.