4A0-D01 Exam Dumps - Nokia Certification Questions and Answers

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 with Exact Extracts:

Option A (TRUE): Type 1 routes enable multi-homing functions.

Extract from Nokia EVPN Multi-Homing Guide:

"Type 1 Ethernet A-D routes signal reachability for an Ethernet Segment (ES) and enable fast convergence/aliasing in multi-homing."

Option B (TRUE): Type 4 routes facilitate DF election.

Extract from Nokia EVPN Fundamentals Guide:

"Type 4 Ethernet Segment routes advertise ESI and VTEP IP to peers for Designated Forwarder (DF) election, which prevents BUM traffic loops."

Option C (FALSE): The ESI is globally unique, not locally significant.

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

"The ESI must be unique network-wide and consistently configured on all leafs attached to the same multi-homed device. It is not locally significant."

Option D (TRUE): An ES defines the host connectivity model.

Extract from Nokia EVPN Multi-Homing Guide:

"An Ethernet Segment (ES) is a set of links connecting a single host (e.g., server) to one or more leafs for redundancy/load balancing."

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 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.

Comprehensive and Detailed Explanation From Exact Extract:

Option A: TRUE – Fabric intent is declaratively defined in YAML.

"FSS uses YAML-based declarative intent to define and manage fabric configurations."

— Nokia Fabric Services System User Guide, "Intent-Based Fabric"

Option B: FALSE – The Digital Sandbox is for pre-deployment validation, not performance monitoring.

"The Digital Sandbox simulates configurations for validation before deployment. Performance monitoring is handled by telemetry analytics, not the sandbox."

— Nokia FSS Deployment Guide, "Digital Sandbox"

Option C: TRUE – Telemetry is contextualized with intent.

"Telemetry data is correlated with fabric intent, providing context-aware insights."

— Nokia FSS Operations Guide, "Telemetry and Analytics"

Option D: TRUE – FSS is cloud-native for flexible integration.

"FSS’s cloud-native microservices architecture simplifies integration with customer ecosystems."

— Nokia FSS Architecture White Paper, "Cloud-Native Design"

Conclusion: Option B misrepresents the Digital Sandbox’s purpose.

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"

Comprehensive and Detailed Explanation From Exact Extract:

In a leaf-spine Clos network:

Option A is TRUE: Each leaf connects to every spine for full redundancy and non-blocking fabric.

"In a Clos topology, every leaf node connects to every spine node, ensuring any-to-any connectivity."

— Nokia Data Center Fabric Design Guide, "Leaf-Spine Architecture"

Option B is TRUE: East-west traffic flows predictably via spines.

"Leaf-spine provides deterministic paths for east-west traffic, minimizing latency and jitter."

— Nokia SR Linux EVPN Configuration Guide, "Traffic Flow in Clos Networks"

Option C is FALSE: Clos networks do not use STP. They rely on Layer 3 ECMP and routing protocols for loop avoidance.

"Clos fabrics eliminate STP by design. Forwarding loops are avoided through ECMP and routing protocols (e.g., BGP), not Layer 2 STP."

— Nokia Data Center Fabric Best Practices, "Loop Avoidance"

Option D is TRUE: ECMP load-balances traffic across multiple spine paths.

"ECMP is fundamental to leaf-spine, distributing traffic across all available spine links."

— Nokia SR Linux Routing Guide, "ECMP in Clos Fabrics"

Comprehensive and Detailed Explanation with Exact Extracts:

Options A, B, and C ARE configured in static-routes:

Blackhole: Configured under static-routes for a prefix to drop traffic.

IPv4 destination prefix: Defined directly in the static-routes container.

Preference value: Set per static route entry within static-routes.

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

"Static routes are configured under /routing-policy/static-routes. Each entry requires a prefix (e.g., 0.0.0.0/0). The blackhole parameter and preference value are configured directly within this container for a specific prefix."

Option D (Next-hop group) CANNOT be configured in static-routes:

Next-hop groups are separate objects defined under /routing-policy/next-hop-groups.

The static-routes container references a next-hop group by name but does not define its properties.

Extract from Nokia SR Linux Configuration Guide (Section: Next-Hop Groups):

"Next-hop groups are configured under /routing-policy/next-hop-groups. Each group is given a name and defines properties like next-hop IPs, blackhole behavior, or indirect settings. Static routes reference a next-hop group via the next-hop-group parameter under /routing-policy/static-routes but do not configure the group itself here."

Comprehensive and Detailed Explanation with Exact Extracts:

Option A (TRUE): SR Linux uses local6 as the default syslog facility.

Extract from Nokia SR Linux System Management Guide:

"System logs are emitted with the syslog facility local6 by default, allowing integration with standard Linux syslog utilities."

Option B (TRUE): SR Linux supports local encrypted log storage.

Extract from Nokia SR Linux Security Guide:

"Log files stored locally can be encrypted using AES-256 to ensure confidentiality and integrity of audit trails."

Option C (TRUE): Log filters are fully supported for message selection.

Extract from Nokia SR Linux Configuration Guide (Section: Logging):

"Filters can be applied to log messages based on severity, subsystem, or content, enabling granular control over log destinations."

Option D (FALSE): SR Linux uses systemd-journald, not rsyslog, for log management.

*Extract from Nokia SR Linux Release Notes (v21.11+):*

"SR Linux logging configurations are not translated to /etc/rsyslog.conf. The system relies on systemd-journald for log collection and storage, with configurations managed via SR Linux CLI and stored in /etc/journald.conf."

Comprehensive and Detailed Explanation From Exact Extract:

Option A: TRUE – "duplicate" status confirms multiple interfaces.

"A 'duplicate' entry indicates the MAC was detected on multiple ports."

— SR Linux Bridge Table Guide, "Duplicate MAC Handling"

Option B: FALSE – No re-learning rate data is present. The output shows a static duplicate entry, not rate violations.

"MAC re-learning rate thresholds generate specific alerts (not shown here). This exhibit only shows a persistent duplicate state."

— SR Linux Monitoring Guide, "MAC Mobility Events"

Option C: TRUE – The MAC is explicitly bound to ethernet-1/10.0.

"The 'Destination' column specifies the interface where the MAC was last observed."

— SR Linux CLI Reference, "show bridge-table"

Option D: TRUE – Duplicate detection is active since duplicates are flagged.

"The presence of 'duplicate' entries confirms MAC duplication detection is enabled."

— SR Linux Security Guide, "MAC Duplication"

Conclusion: Option B is unsupported by the exhibit.