300-435 Sample Questions & Answers

A synchronous API call blocks the calling code until the server returns a response. If the response is slow or never arrives, the application waits, which adds perceived latency. Synchronous calls can be made from any language and are not inherently less portable. Not blocking while the request is processed describes asynchronous calls.

A synchronous API call blocks the calling code until the server returns a response. If the response is slow or never arrives, the application waits, which adds perceived latency. Synchronous calls can be made from any language and are not inherently less portable. Not blocking while the request is processed describes asynchronous calls.

Action Batches allow you to send multiple configuration requests in a single API call. This reduces the number of HTTP requests, helping to stay within rate limits, and supports 'atomic' transactions where either all changes are applied or none are, ensuring configuration consistency.

In RESTCONF, operational data (status) is typically accessed via the interfaces-state container (in RFC 7223/8343 models) or similar state containers. The /restconf/data root is correct, and GET is the correct verb for retrieval. Accessing configuration data would use the interfaces container.

edit_config(..., default_operation='replace') adds replace to the RPC. The NETCONF default is merge; with replace, RFC 6241 §7.2 states that the configuration data in the parameter completely replaces the configuration in the target datastore, so anything not in the payload is removed. (To replace only one container or list entry, keep the default merge and put the operation="replace" attribute on that element in the XML.) error_option='rollback-on-error' only controls error handling, target='startup' is not an edit-config target on IOS XE (edits go to running, or candidate when enabled), and ncclient's format accepts 'xml', 'text' or 'url', not 'json'.

The Authorization header (often Basic Auth or a Bearer Token) configured in the DNA Center webhook destination is sent from DNA Center to the external system, allowing the external system to verify that the incoming HTTP request is legitimate and authorized.

git rebase re-applies commits from the current branch on top of another base tip (e.g., origin/main). This creates a linear history without the extra 'merge commit' that git merge produces, which is often preferred for cleaner history.

The vManage authentication flow typically requires an initial POST to j_security_check with username/password to get the session cookie (JSESSIONID).

After obtaining the session ID, a second call to retrieve the XSRF token is necessary for performing any POST/PUT/DELETE operations to prevent Cross-Site Request Forgery.

This statement is backwards. A 'container' exists only once (singleton) and groups related nodes. A 'list' can have multiple instances (like rows in a table), each identified by a key.