4A0-D01 Nokia Data Center Fabric Fundamentals Exam Questions and Answers

Comprehensive and Detailed Explanation From Exact Extract:

Option A is TRUE: SR Linux is fully model-driven.

"Every configuration and state element in SR Linux is defined by a YANG model."

— SR Linux YANG Data Modeling Guide, "Introduction"

Option B is FALSE: Containers are branches (grouping nodes), and leafs are data components (terminal values). The description is reversed.

"YANG structures data hierarchically: containers organize child nodes (branches), while leafs hold actual data values (e.g., integers, strings)."

— SR Linux YANG Data Modeling Guide, "Tree Structure"

Option C is TRUE: YANG supports JSON/XML encoding.

"YANG models serialize natively to XML or JSON for machine-to-machine communication."

— SR Linux gNMI and JSON-RPC Guide, "Data Encoding"

Option D is TRUE: YANG enables standardized access via gNMI/NETCONF.

"YANG provides a consistent schema for applications to retrieve/configurate data via protocols like gNMI."

— SR Linux Automation Guide, "Model-Driven Interfaces"

The "baseline diff" command is used to compare the candidate configuration against the baseline datastore to see changes or conflicts, especially when multiple users are involved or to verify differences. It does not indicate that the user is unable to commit changes.

Comprehensive and Detailed Explanation with Exact Extracts:

Options A, B, and C are part of ZTP autoboot:

A: DHCP assigns IP/gateway.

B/C: Scripts download images/RPMs from servers (HTTP/FTP).

Extract from Nokia SR Linux ZTP Guide:

"Autoboot triggers DHCP discovery for IP/gateway. The device then fetches a provisioning script (via DHCP/DNS) that downloads RPMs/images from HTTP/FTP servers."

Option D is NOT part of ZTP autoboot:

Fabric Services System (FSS) and its digital sandbox are separate tools for lifecycle management. ZTP does not auto-deploy them.

Extract from Nokia FSS Deployment Guide:

"FSS deployment requires manual setup or orchestration tools. The digital sandbox is not automatically deployed via ZTP autoboot."

Comprehensive and Detailed Explanation with Exact Extracts:

Option B (CPM-filter ACL) is CORRECT:

The CPM-filter ACL is explicitly designed to match control-plane traffic and copy it to the CPM (Control/Management Plane). It is instantiated in hardware on all line cards.

Extract from Nokia SR Linux Security Guide (Section: Control Plane Protection):

"The cpm-filter ACL is instantiated on every line card to identify packets destined for the CPM (e.g., routing protocols, ICMP). Matched packets are copied to the CPM while data-plane traffic is forwarded normally."

Other Options are INCORRECT:

A: Capture-filter ACL is for packet mirroring (e.g., SPAN), not CPM copying.

C/D: Ingress/Egress ACLs filter user traffic and are not specific to CPM-bound packets.

Extract from Nokia SR Linux ACL Configuration Guide:

"Only cpm-filter ACLs are globally applied across line cards for CPM protection. Interface ACLs (ingress/egress) operate locally and do not copy packets to the CPM."

Comprehensive and Detailed Explanation From Exact Extract:

The SR Linux Application Manager (app_mgr):

Option A is TRUE: Monitors application health and restarts failed processes.

"The Application Manager monitors the status of all running applications and triggers recovery actions if failures occur."

— SR Linux System Management Guide, "Application Manager"

Option B is TRUE: Manages both Nokia-provided and user-added containerized applications.

"app_mgr manages the lifecycle of all applications, whether preinstalled by Nokia or custom-developed by users."

— SR Linux DevOps Guide, "Custom Application Deployment"

Option C is TRUE: Parses application manifests and launches applications.

"The Application Manager reads manifest files (including configuration) and starts applications accordingly."

— SR Linux Configuration Fundamentals, "Application Initialization"

Option D is FALSE: Translation of YANG to protobuf is handled by the Management Server (mgmt_server), not app_mgr.

"The Management Server (mgmt_server) compiles YANG models into protobuf schemas for the Interface Database (IDB). The Application Manager does not handle model translation."

— SR Linux Architecture White Paper, "Data Modeling Components"

Comprehensive and Detailed Explanation:

Nokia’s Fabric Services System (FSS) employs an intent-driven approach where the fabric intent is defined in a YAML file. This file specifies the desired state of the data center fabric, including topology, services, and policies. FSS translates this declarative intent into device-specific configurations.

Exact Extract:

"Fabric Services System uses intent-based YAML templates to define the fabric’s target state. The system automates configuration generation and deployment, ensuring consistency across the fabric."

Comprehensive and Detailed Explanation with Exact Extracts:

Option A (VNI is included): The IMET route explicitly carries the VNI (as the Ethernet Tag ID) to identify the Layer 2 domain.

Extract from Nokia EVPN-VXLAN Guide (Section: IMET Route):

"The IMET (Type 3) route includes the VNI (Ethernet Tag ID) to signal membership in a specific broadcast domain."

Option B (Flooding list is NOT included): The IMET route does not contain a flooding list. Each VTEP independently builds the flooding list by aggregating all received IMET routes for the same VNI (e.g., VTEP1 uses IMET routes from VTEP2 and VTEP3 to build its list).

Extract from Nokia SR Linux Fundamentals Guide (Section: EVPN BUM Handling):

"The flooding list for a VNI is dynamically constructed by each VTEP based on received IMET routes. The IMET route itself only advertises the sender's VTEP IP and VNI, not a pre-defined list of peers."

Option C (Route Distinguisher is included): The IMET route includes the MAC-VRF's Route Distinguisher (RD) to ensure uniqueness in the control plane.

Extract from Nokia EVPN Configuration Guide:

"Every IMET route carries the MAC-VRF's RD to distinguish overlapping VNIs across different network instances."

Option D (VTEP IP is included): The IMET route advertises the VTEP's IP address (via the PMSI Tunnel attribute) to establish the BUM traffic tunnel endpoint.

Extract from Nokia SR Linux Configuration Guide (Section: EVPN Routes):

"The IMET route includes the originating VTEP's IP address in the PMSI Tunnel field. This IP is used as the destination for VXLAN-encapsulated BUM traffic."

Exhibit Analysis:

The IMET routes (advertised by VTEP1, VTEP2, VTEP3) are shown.

Each VTEP's locally configured flooding list (e.g., VTEP1: [VTEP2, VTEP3]) is derived from received IMET routes, not embedded in the IMET route itself.