4A0-D01 Practice Exam Questions with Answers Nokia Data Center Fabric Fundamentals Exam Certification

Comprehensive and Detailed Explanation with Exact Extracts:

Options A, B, and D are supported:

SR Linux users (A): Locally configured users for CLI/management access.

Regular Linux OS users (B): Native Linux users (e.g., admin) for host OS operations.

Remote users (D): Authenticated via AAA (TACACS+/RADIUS).

Extract from Nokia SR Linux System Management Guide:

"User types include SR Linux users (CLI access), Linux OS users (host system), and remote users (external AAA)."

Option C (Container users) is NOT supported:

SR Linux does not define "container users" as a distinct category. Containers (e.g., management container) share the host's user management.

Extract from Nokia SR Linux Security Guide:

"SR Linux does not provision separate user identities for containers. User access is managed at the host OS level or via SR Linux CLI, with no container-specific user type."

Comprehensive and Detailed Explanation From Exact Extract:

Option A: TRUE – MAC-VRF is a Layer 2 instance.

"A MAC-VRF network instance operates as a Layer 2 bridging domain."

— SR Linux Network Instance Guide, "MAC-VRF Overview"

Option B: TRUE – Bridge tables map MACs to egress interfaces.

"The bridge table associates destination MAC addresses with exit interfaces."

— SR Linux Forwarding Guide, "MAC-VRF Forwarding"

Option C: FALSE – MAC-VRF uses MAC addresses (not IP) for forwarding.

"In a MAC-VRF, traffic is switched based solely on destination MAC addresses, not IP."

— SR Linux Network Instance Guide, "Bridging vs Routing"

Option D: TRUE – MAC-VRF groups devices in the same subnet.

"A MAC-VRF instance enables Layer 2 connectivity for devices sharing the same IP subnet."

— SR Linux EVPN Guide, "L2 Network Design"

Conclusion: Option C is false as MAC-VRF is L2-only.

Comprehensive and Detailed Explanation From Exact Extract:

Option A: TRUE – SR Linux leverages an unmodified Linux kernel for broad third-party compatibility.

"SR Linux uses a standard, unmodified Linux kernel, enabling seamless integration of third-party applications."

— Nokia SR Linux Technical Overview, "Linux Foundation"

Option B: TRUE – Its state-driven architecture (centered on the Interface Database) enables efficient data access.

"The state-driven architecture provides applications with granular, real-time access to system state via the IDB."

— SR Linux Architecture White Paper, "State-Driven Design"

Option C: TRUE – The NetOps Development Kit (NDK) (not "NetOgs") supports third-party app integration.

"The NetOps Development Kit (NDK) offers tools and libraries for third-party application development and integration."

— SR Linux DevOps Guide, "NDK Overview"

Option D: FALSE – SNMP is not used for CLI access. SR Linux uses gNMI, JSON-RPC, or SSH/CLI.

"SR Linux CLI is accessed via SSH or modern interfaces (gNMI/JSON-RPC). SNMP is supported only for legacy monitoring, not CLI interaction."

— SR Linux Management Interfaces Guide, "Protocol Support"

Conclusion: Option D is incorrect as SNMP is not a CLI access method.

Comprehensive and Detailed Explanation with Exact Extracts:

Options A, B, and C are TRUE:

A: BFD detects microsecond-level link failures, faster than BGP timers.

B: BFD negotiates a control-packet rate during session setup.

C: Missed BFD packets trigger a session-down event, notifying BGP.

Extract from Nokia SR Linux Configuration Guide (Section: BFD for BGP):

"BFD provides sub-second failure detection. Peers negotiate tx-interval and rx-interval timers dynamically. If the configured multiplier threshold of missed packets is reached, BFD notifies BGP to tear down the session."

Option D is FALSE: BFD does not modify BGP’s update timers (e.g., min-advertisement-interval). It only accelerates failure detection.

Extract from Nokia SR Linux Fundamentals Guide (Section: BFD Integration):

"BFD does not influence BGP’s route advertisement or withdrawal timers. It solely enhances failure detection speed, allowing BGP to react faster to topology changes."

Comprehensive and Detailed Explanation From Exact Extract:

Option A: TRUE – state mode shows configuration + operational state.

"The state command provides a unified view of configuration and real-time operational data."

— SR Linux CLI User Guide, "State Mode"

Option B: TRUE – show mode uses predefined templates.

"show commands use structured report templates for consistent operational data display."

— SR Linux CLI User Guide, "Show Commands"

Option C: TRUE – running mode is for configuration changes.

"Configuration edits occur in running mode, which modifies the candidate configuration."

— SR Linux Configuration Fundamentals, "CLI Modes"

Option D: FALSE – use (not enter) switches modes.

"Mode transitions use the use command (e.g., use state). enter navigates hierarchical paths within a mode."

— SR Linux CLI User Guide, "Mode Navigation"