Cisco 200-901: Automating Networks Using Cisco Platforms (CCNAAUTO)

Incorrect. Microservices can complement DevOps by enabling independent deployments and smaller change sets, but they are an architectural style, not a foundational DevOps principle. DevOps can be implemented with monoliths or microservices. Treat microservices as a possible outcome/choice, not a definition of DevOps.

Incorrect. Containers are a deployment technology that often supports DevOps goals (portability, consistency, faster deployments), but DevOps does not require containers. Many DevOps implementations use VMs, bare metal, or platform services without containers. Exams typically classify containers as tooling, not foundational principles.

Incorrect. Optimizing infrastructure cost is a valid business goal and may be improved through DevOps/FinOps practices, but it is not a foundational DevOps principle. DevOps primarily focuses on delivery speed, stability, collaboration, and continuous improvement; cost optimization is secondary and context-dependent.

Incorrect. Functions provide abstraction, meaning a developer can call a function without fully understanding its internal implementation (for example, using a library function). While reading a function can help understanding, there is no guarantee or enforcement that a developer understands the inner logic before using it. The key benefit is encapsulation and reuse, not ensuring comprehension.

Incorrect. Functions are a general programming construct used to organize and reuse code. They can be used to implement cryptographic algorithms, but that is a specific application, not an inherent benefit of functions. The statement also implies secrecy/encryption as a primary purpose, which is unrelated to why functions exist in programming.

Incorrect. Storing mutable values is the role of variables, data structures, or objects. Functions may create local variables or modify external state, but their purpose is to encapsulate behavior/logic. Confusing functions with storage is a common beginner mistake; functions define actions, while variables hold data.

Incorrect. A switch is not uniquely identified by a single MAC address in the general sense. Switches have multiple MAC addresses (per port) and may also have a separate management/interface MAC. While a switch learns and uses MAC addresses to forward frames, the purpose of a MAC address is to identify a Layer 2 interface, not specifically “a switch.”

Incorrect. Routers operate primarily at Layer 3 and are identified for routing purposes by IP addresses. Routers do have MAC addresses on their Ethernet interfaces, but those MACs identify the router’s interfaces on the local LAN, not the router as a whole. The router rewrites Layer 2 headers at each hop, reinforcing the local scope of MAC addresses.

Incorrect. Devices on the Internet are not uniquely identified by MAC addresses because MAC addresses are not routable and are only relevant within the local Layer 2 segment. Across routed networks, the Layer 2 header changes at every hop. End-to-end identification and routing on the Internet rely on IP addresses (and higher-layer identifiers like DNS names).

False. PC-B is connected to the LAN labeled 192.168.1.0/24, which means the subnet uses a 24-bit network prefix. A statement claiming 18 bits are dedicated to the network portion would correspond to a /18 mask, not /24. Therefore the diagram contradicts this option directly.

False. R1 and R3 do not share a common subnet with each other. R1 connects to R2 using 10.1.1.0/30, while R3 connects to R2 using 10.2.2.0/30, and those are distinct Layer 3 networks. Since each router interface belongs to its own labeled /30 subnet, R1 and R3 are not in the same subnet.

False. PC-C is on subnet 192.168.3.0/24, and a /24 contains 256 total IP addresses. However, two of those addresses are reserved for the network and broadcast addresses, leaving only 254 usable host addresses in traditional IPv4 subnetting. So the subnet cannot contain 256 hosts.

Removing “unnecessary tests” is not a standard approach to organizing code and can reduce reliability. Tests (unit/integration) are typically kept or improved during refactoring to ensure behavior doesn’t change. The problem described is duplicated implementation, not excessive validation logic. Eliminating tests may make the code shorter, but it does not improve structure, reuse, or maintainability and is generally a poor practice.

Reverse engineering and rewriting the logic is excessive and risky, especially since the code “runs fine.” Good refactoring is behavior-preserving and incremental: you improve structure without changing what the program does. A full rewrite increases the chance of introducing defects and is not the typical answer for organizing repeated code. Exam-wise, rewrites are rarely the best first step when a targeted refactor solves the issue.

Loops reduce repetition when the same operation is performed over a list (for example, configuring many devices or interfaces). However, loops alone don’t necessarily “organize” code when the repetition occurs in multiple places or represents a reusable procedure. Often, the best design is a function that performs the task and a loop that calls it for each item. Since the question emphasizes organizing repeated pieces, functions are the more direct answer.

Incorrect. Although the first task sets Gi0/1 to state: unconfigured, the very next task configures Gi0/1 with mode: trunk and state: present. In Ansible, tasks are applied in order, so the final configuration is the trunk configuration, not an unconfigured interface.

Incorrect. A trunk on Gi0/1 does not enable traffic to flow between ports 0/2 to 0/5 by itself. Ports communicate at Layer 2 only if they are in the same VLAN. Here, Gi0/2 and Gi0/3 are in VLAN 6, Gi0/4 is in VLAN 7, and nothing is stated about Gi0/5. Inter-VLAN traffic would require routing, not just a trunk.

Incorrect. The playbook does not reference GigabitEthernet0/6 at all, and there is no configuration that would connect traffic from Gi0/2 and Gi0/3 specifically to Gi0/6. The only uplink-like configuration shown is the trunk on Gi0/1, which carries VLANs 6-8, not a mapping to Gi0/6.

Incorrect. The function uses HTTPBasicAuth(DNAC_USER, DNAC_PASSWORD) to authenticate the POST request to the DNAC token endpoint, but it does not return the Basic Auth object or credentials. Basic authentication is only the method used to obtain the token; the returned value is taken from the JSON response body, not from the Basic Auth mechanism itself.

Incorrect. DNAC_USER and DNAC_PASSWORD are variables supplied to HTTPBasicAuth as inputs to the request. The function never returns these values. Instead, it parses the HTTP response JSON and returns the value of the 'Token' field, which is generated by DNAC after validating the provided username and password.

Incorrect. There is no file I/O in the function—no open(), no reading of a JSON file, and no posting of a locally stored token. The token is obtained directly from the DNAC API response to the POST request. The only POST is to the DNAC URL to request a new token using Basic Auth.

Checkout is the act of retrieving a branch/commit into a working directory to view or modify files. Code review is not typically performed before checkout; reviewers must usually access the code (via a PR diff or by checking out the branch) to review it. Checkout is a prerequisite to making changes, not a gate that review controls.

Committing records changes into version control history, often locally and frequently during development. While developers may self-review before committing, formal team code review is generally not required before each commit. The formal review process is usually tied to a PR/MR and enforced before merging into a shared branch.

Branching creates an isolated line of development (feature branch, bugfix branch, etc.). Code review is not performed before branching; branching is a workflow step to enable parallel work. Review occurs after changes are made on the branch and proposed for integration, typically right before merge.

Incorrect. In TDD, developers write automated tests (typically unit tests) as part of the development process. User acceptance testers may define acceptance criteria or run UAT, but they do not typically develop the test requirements that drive TDD’s test-first cycle. This option describes a QA/UAT process rather than developer-led test-first development.

Incorrect. Writing tests only when code is ready for release is the opposite of TDD. TDD requires tests to be written before (or at least alongside) implementation, continuously guiding design and catching defects early. Late test creation aligns more with traditional QA phases and increases the risk of discovering issues when changes are more expensive.

Incorrect. Incremental testing of release candidates describes iterative validation during packaging/release management, not TDD. TDD drives implementation at the code level with small unit tests written first, not by testing “release candidates.” While CI/CD may test builds frequently, TDD’s defining trait is test-first development guiding code design.

Incorrect. The script does not iterate over all directories in the current folder (there is no `for` loop, no glob like `*`, and no directory listing). It only uses a single user-provided directory name (`ndir`) and repeatedly checks for that specific directory name as it changes into it.

Incorrect. It does not always “go into the directory entered and create a new directory with the same name” at that same level. If the directory exists, it goes into it and keeps going deeper as long as another directory with the same name exists. The `mkdir` occurs only after the loop ends, at the deepest level reached.

Incorrect. `$ndir` is a variable expanded by the shell; it is not a literal directory name “$ndir”. Also, the script does not necessarily go into a directory called `$ndir` once and then create another `$ndir` alongside it; it may traverse multiple nested levels before creating the missing directory.

The response body contains the resource representation (often JSON/XML) or error details. While some APIs include a "success" flag or error message in the body, this is not standardized and may be absent (for example, 204 No Content). Best practice is to check the HTTP status code first, then parse the body only when appropriate.

Headers carry metadata such as Content-Type, Location (for newly created resources), authentication challenges (WWW-Authenticate), and rate-limit information. They can influence behavior (e.g., follow a Location URL after 201), but they are not the primary element used to determine whether the request succeeded. That determination is standardized via the status code.

A link is typically a URL reference provided either in the body (HATEOAS-style) or via headers like Link. Links help clients discover related resources or pagination, but they do not indicate whether the API call was valid or successful. Success/failure is still communicated through the HTTP status code.

The URL is part of the request, identifying the endpoint and resource path. It is not an element of the response used to validate success. A correct URL can still produce failures (401, 403, 500), and an incorrect URL often yields 404. The client should evaluate the response status code to determine outcome.

Changing GET to PUT does not resolve a 401 error. GET is the correct RESTCONF method for retrieving configuration/state data. PUT is used to create or replace a resource (write operation) and would likely introduce different errors (such as 405 Method Not Allowed or 403/409) if the server rejects the write. A 401 specifically points to authentication, not the HTTP verb.

MIME type issues relate to RESTCONF content negotiation using the Accept and Content-Type headers (e.g., application/yang-data+json or application/yang-data+xml). If these are wrong, the server typically returns 406 (Not Acceptable) or 415 (Unsupported Media Type), not 401. While headers are important in RESTCONF, they are not the primary fix for an Unauthorized response.

Switching from HTTP to HTTPS may be required by a security policy, but it does not inherently fix a 401 Unauthorized response. If the device only allows HTTPS, using HTTP would more commonly fail with connection issues or redirects, not an authentication failure. Even over HTTPS, the client must still provide valid credentials; otherwise, the server will continue to return 401.

A payload limit refers to a maximum message size, typically measured in bytes, and it can apply to requests, responses, or both depending on the API or gateway implementation. If a payload-size threshold were the issue, the behavior would usually depend on the total serialized size of the returned data rather than always stopping at exactly 25 records. APIs also more commonly signal payload-size problems with an error or require filtering, compression, or smaller queries. A fixed and repeatable record count is much more characteristic of pagination than of a payload-size control.

Service timeouts occur when the server or an intermediary cannot complete processing within a time threshold, often resulting in errors such as 408 Request Timeout or 504 Gateway Timeout. Timeouts do not normally produce a successful response with a predictable, fixed number of records; they more commonly cause failures or incomplete operations.

Rate limiting controls how many API calls a client can make in a given time window to protect the service. When exceeded, the API usually responds with 429 Too Many Requests and may include retry-after guidance. Rate limiting affects request frequency, not the number of records returned per successful request.

A buffer overflow due to a low-level language is an application security/stability issue, but it doesn’t fit the scenario well. The script runs successfully and consistently produces log bundles, indicating it is not crashing or corrupting memory. Also, a buffer overflow in a client script would not typically disrupt enterprise-wide voice quality unless it compromised critical infrastructure, which would likely show broader symptoms than only call quality during execution.

Incorrect speed/duplex settings would cause persistent link issues (errors, collisions, retransmissions) and would impact traffic continuously, not only when the log bundle script runs. Additionally, Cisco DNA Center speed/duplex settings are not typically the bottleneck for generating a log bundle; the heavy work is local CPU/disk processing on the controller, not a slow Ethernet transfer caused by duplex mismatch.

The script “running in the Voice VLAN” is a misunderstanding. VLANs segment Layer 2 broadcast domains; they don’t inherently cause jitter unless the network is congested or QoS is misconfigured. A log bundle generation task is executed on Cisco DNA Center (controller-side), not as a host generating significant traffic inside the voice VLAN. Even if the script downloads the bundle, that traffic would usually be best-effort and should be handled by QoS, not automatically disrupt voice.

Webex Teams (now generally referred to as Webex messaging APIs) is used to manage spaces, messages, memberships, and some user-related collaboration functions in the Webex cloud. It does not provide inventory/configuration data for CUCM voicemail ports, which are on-prem telephony objects tied to call routing and Unity Connection integration. Choosing this option is a common confusion between “voicemail” as a concept and Webex messaging services.

Finesse Gadgets relate to Cisco Finesse, a contact center desktop platform (commonly used with UCCX/UCCE). Finesse APIs and gadgets focus on agent state, dialogs, call control, and desktop UI integrations. They do not provide authoritative configuration data for CUCM voicemail ports. This option may seem plausible if you associate “ports” with call handling, but it’s the wrong platform for voicemail port inventory.

Webex Devices APIs are used to manage and monitor Webex Room/Desk devices and related cloud-managed endpoints (status, configuration, xAPI commands). Voicemail ports are not Webex devices; they are CUCM telephony constructs used for voicemail integration. As a result, Webex Devices APIs cannot be used to obtain voicemail port configuration data in CUCM.