200-901 Practice Test 32 — 15 Questions

Question 1

Which YANG model is an OpenConfig model used for interface configuration?

Accepted Answer

openconfig-interfaces. OpenConfig is a vendor-neutral, community-driven data model standard for network configuration and state. The 'openconfig-interfaces' YANG model is the OpenConfig model specifically designed for interface configuration, providing a consistent, model-driven approach across different network operating systems. Option D is correct because it directly names the OpenConfig model for interfaces.

Answer

oc-yang-interfaces

Answer

ietf-interfaces

Answer

Cisco-IOS-XE-interfaces

Question 2

A DevOps team is deploying a microservices application that requires both reliable data transfer and low-latency real-time communication. Which two protocols should be used for these respective requirements? (Choose two.)

Accepted Answer

TCP. TCP (Transmission Control Protocol) is correct for reliable data transfer because it provides connection-oriented communication with sequencing, acknowledgments, and retransmission of lost packets, ensuring data arrives intact and in order. This makes it ideal for microservices that need guaranteed delivery, such as database transactions or order processing.

Answer

ARP

Answer

ICMP

Answer

HTTP

Question 3

Which NX-OS API method allows sending CLI commands in JSON format without enabling any additional features?

Accepted Answer

NX-API method 'cli' with JSON encoding. NX-API on NX-OS supports both JSON-RPC (with method 'cli' or 'cli_ascii') and JSON encoding for CLI commands. The method 'cli' or 'cli_ascii' in JSON-RPC format is used.

Answer

RESTCONF with YANG data

Answer

SNMP with MIB objects

Answer

NETCONF with XML data

Question 4

An engineer is troubleshooting a network issue and needs to verify the MAC address of the next-hop router on a directly connected segment. Which layer of the OSI model does the engineer need to examine to find this information?

Accepted Answer

Data Link layer (Layer 2). The MAC address of the next-hop router is found in the Data Link layer (Layer 2) header of a frame. When a device sends an IP packet to a next-hop router on the same segment, it encapsulates the packet in a frame with the destination MAC address of that router's interface. To verify this address, you examine Layer 2 information, such as by using the `show arp` command on Cisco devices to view the MAC-to-IP mapping.

Answer

Transport layer (Layer 4)

Answer

Physical layer (Layer 1)

Answer

Network layer (Layer 3)

Question 5

Which TWO of the following are benefits of using UDP over TCP for real-time applications?

Accepted Answer

Lower latency due to no connection setup. UDP does not require a three-way handshake (SYN, SYN-ACK, ACK) before data transmission, eliminating the connection setup latency inherent in TCP. This makes UDP ideal for real-time applications like VoIP or video streaming where low delay is critical.

Answer

Guaranteed delivery of all packets

Answer

In-order packet delivery

Answer

Congestion control to avoid network overload

Question 6

Refer to the exhibit. An automation script expects the interface IP address to be configured via DHCP. Based on the output, what is the current configuration source for the IP address?

Accepted Answer

Manual configuration (NVRAM). The output shows 'IP address is 192.168.1.1, subnet mask is 255.255.255.0' with no DHCP or BOOTP flags, and the configuration is stored in NVRAM (startup-config). This indicates the IP was manually configured (typed by an administrator) and saved, not obtained via DHCP. Option C is correct because the source is manual configuration from NVRAM.

Answer

DHCP

Answer

BOOTP

Answer

PPP negotiation

Question 7

Which Meraki API response header provides information for paginating through a large result set?

Accepted Answer

Link. Meraki uses the Link header (LinkHeader) with 'next' and 'prev' URLs, or alternatively the startingAfter/endingBefore parameters. The Link header is standard for pagination.

Answer

Content-Range

Answer

X-RateLimit-Remaining

Answer

Retry-After

Question 8

A network automation engineer is developing a Python script that uses the NETCONF protocol to retrieve the running configuration from a Cisco IOS XE device. They use the ncclient library. The script works on the test device but fails on a production device with an error: "ncclient.transport.errors.AuthenticationError: Authentication exception". The engineer verifies that the SSH credentials (username and password) are correct and that the production device is reachable via SSH on port 830. What is the most likely issue?

Accepted Answer

The production device requires SSH key-based authentication, but the script uses password.. The error 'AuthenticationException' from ncclient indicates that the NETCONF session over SSH failed during authentication. Since the engineer verified the password is correct and the device is reachable on port 830, the most likely cause is that the production device is configured to require SSH key-based authentication (e.g., using 'ip ssh server algorithm authentication publickey' or similar), while the script is attempting password-based authentication. ncclient defaults to password authentication unless explicitly configured with a key filename.

Answer

The production device uses a different port for NETCONF than the test device.

Answer

The production device has a firewall rule blocking NETCONF capabilities.

Answer

The production device does not have NETCONF enabled; it only supports SSH.

Question 9

When using RESTCONF to configure a network device, what Content-Type header should be set in the HTTP request to indicate YANG data in JSON format?

Accepted Answer

application/yang-data+json. RESTCONF uses application/yang-data+json for JSON encoding of YANG data.

Answer

application/yang

Answer

application/xml

Answer

application/json

Question 10

A company is implementing a secure CI/CD pipeline. Which THREE practices are essential for securing the pipeline?

Accepted Answer

Sign and verify all build artifacts.. Signing and verifying build artifacts ensures integrity and authenticity, preventing tampered artifacts from being deployed. This is a core supply chain security practice, often implemented using tools like GPG or Sigstore (Cosign) to generate and validate cryptographic signatures. Without verification, an attacker could inject malicious code into the pipeline by replacing a signed artifact with a compromised one.

Answer

Allow all container images to be pulled from any public registry.

Answer

Store secrets (API keys, passwords) in version control.

Question 11

Which HTTP method is idempotent and safe?

Accepted Answer

GET. GET is both idempotent and safe because it is designed to retrieve a resource without causing any side effects on the server. According to RFC 7231, a safe method does not modify the resource state, and an idempotent method guarantees that multiple identical requests produce the same result as a single request. GET satisfies both conditions, as it never alters server state and repeating the same GET request returns the same representation.

Answer

DELETE

Answer

POST

Answer

PUT

Question 12

What HTTP method should be used to update only the description field of a network device resource via a REST API?

Accepted Answer

PATCH. PATCH is used for partial updates, whereas PUT replaces the entire resource. GET retrieves, POST creates, DELETE removes.

Answer

DELETE

Answer

PUT

Answer

POST

Question 13

A Kubernetes pod contains two containers that need to share a local filesystem. Which volume type should be used to enable this?

Accepted Answer

emptyDir. An emptyDir volume is created empty when a pod is assigned to a node and exists as long as the pod runs; it can be mounted by multiple containers within the same pod.

Answer

hostPath

Answer

configMap

Answer

persistentVolumeClaim

Question 14

Refer to the exhibit. A network engineer applies this JSON-based QoS policy to a Cisco device using NETCONF/YANG. Which statement best describes the expected behavior for traffic from 10.0.0.0/24 with DSCP EF?

Accepted Answer

Traffic from 10.0.0.0/24 with DSCP EF is re-marked to AF41 and limited to 100 Mbps; excess is dropped.. The JSON-based QoS policy uses a class map matching traffic from source 10.0.0.0/24 with DSCP EF, then applies a police action that re-marks exceeding traffic to AF41 and drops it when the rate exceeds 100 Mbps. This is a standard two-rate policer behavior in Cisco IOS QoS, where conforming traffic is transmitted unchanged and exceeding traffic is re-marked and dropped.

Answer

Traffic with DSCP EF from any source is re-marked to AF41 and dropped if exceeding 100 Mbps.

Answer

The policy is invalid because DSCP values cannot be changed in a QoS policy.

Answer

Traffic from 10.0.0.0/24 is re-marked to DSCP EF, then policed at 100 Mbps.

Question 15

In Software-Defined Networking (SDN), which interface is used for communication between the controller and the network devices (e.g., switches) to forward traffic?

Accepted Answer

Southbound API. The southbound API (e.g., OpenFlow, NETCONF) is used to communicate between the SDN controller and the data plane devices.

Answer

Northbound API

Answer

Control plane

Answer

East-West API