300-535 Automating and Programming Cisco Service Provider Solutions (SPAUTO) Practice Questions

In RESTCONF (and REST in general), PUT is used to replace an entire resource. If you PUT to an interface configuration, you must provide the complete configuration for that interface, and any unspecified attributes will be deleted. PATCH is used for partial updates. You only need to provide the data for the specific attributes you want to change (like the description), and all other attributes of the resource will remain untouched. This makes PATCH ideal for targeted changes.

This is a core concept of NSO. The Device Manager component uses NEDs, which are plugins that contain the logic to translate the standardized YANG data models into the specific command syntax (e.g., IOS XR CLI, Junos XML) of the target device.

The CDB is a central component of NSO. It is a high-performance, in-memory XML database that stores the configuration for services and devices. All operations on the CDB are transactional, ensuring data integrity and providing rollback capabilities.

This statement is false. The gNMI Subscribe RPC supports three subscription modes: ONCE, POLL, and STREAM. The ONCE mode is used to retrieve a snapshot of the requested data and then the RPC terminates, which is analogous to a or operation in NETCONF. STREAM subscriptions are for continuous data streaming.

According to the ietf-interfaces YANG model, the top-level container is interfaces. Inside this container is a list named interface. In JSON, a YANG list is represented as an array. Each object within the array represents an entry in the list, identified by its key(s), which in this case is name. Therefore, the correct structure is a top-level interfaces object containing an interface array, with one object for 'GigabitEthernet0/0/0' inside it.

The Cisco XR Traffic Controller (XTC), also known as the Segment Routing Path Computation Element (SR-PCE), is the specific component designed for this role. It maintains a real-time view of the network topology (often learned via BGP-LS), computes SR policy paths based on constraints (like latency or bandwidth), and uses protocols like PCEP to instantiate and manage these policies on the network's headend routers. NSO is for orchestration, WAE is for offline planning, and Crosswork is a broader automation suite.

The must statement in YANG is used to define a constraint on a data node. It takes an XPath expression as an argument. This expression is evaluated, and if it returns false, the configuration is considered invalid. This is the ideal tool to enforce that if a bandwidth leaf exists or has a certain value, a corresponding QoS policy leaf must also exist and be configured correctly, thus creating a direct, model-enforced dependency. augment adds to another model, when makes a node conditional, and grouping is for reusable blocks, none of which enforce a cross-leaf validation constraint like must.

This is a correct subtree filter. It specifies the top-level container bgp and correctly identifies its namespace urn:ietf:params:xml:ns:yang:ietf-bgp. This will return the entire BGP configuration.

This is a correct XPath filter. It defines a prefix ietf-bgp for the namespace and uses it in the XPath expression /ietf-bgp:bgp to uniquely select the BGP configuration container. XPath filters require namespace prefixes for non-default namespaces.

git rebase main rewrites the commit history of the current branch (feature-bgp-policy) on top of the latest commit from the main branch. This process avoids creating a merge commit and results in a clean, linear history. git merge would create a merge commit, git pull is for fetching and merging from a remote, and git cherry-pick applies a single commit.

For gRPC dial-out telemetry on IOS XR, the subscription configuration requires specifying the protocol and security level. The grpc keyword is used, and it must be followed by either tcp for cleartext transport or tls for encrypted transport. The keyword no-tls is a sub-option under the grpc protocol configuration within the destination-group, not the subscription itself. The question implies a standard gRPC connection and in the subscription context, grpc is the main keyword. However, the full command in the destination group for dial-out is grpc and then sub-options like no-tls. The most common configuration mistake is in the destination-group. Let's re-evaluate the question context. The blank is in the subscription, which points to a destination group. The prompt is slightly misleading. The protocol keyword is actually under the destination group. Let's assume the question meant the destination-group config. In that case, grpc would be the protocol. The most appropriate keyword in the context of a subscription pointing to a gRPC destination is simply 'grpc'. Let's find a more suitable question. Let's reformulate.

Correct Question & Answer: A network operator is configuring a gRPC dial-out destination group. Which keyword must be configured under the destination group to specify unencrypted transport? The correct answer is no-tls. The original question was flawed. The blank should be in the destination group. Let's correct it for this format. Let's assume the original question meant to test the dial-out keyword. In the destination-group, you would specify protocol grpc no-tls. Therefore, no-tls is the keyword to disable encryption. We will stick with this interpretation.

This statement is false. The diff_replace: line parameter instructs Ansible to perform a line-by-line comparison and merge, which is the default behavior. To replace an entire configuration block, you would set diff_replace: block. The line option ensures that only the specified lines in the playbook task are added or modified, preserving other configurations within the same block.