Nokia 4A0-100 Nokia IP Networks and Services Fundamentals Exam Practice Test

Answer : D

In the diagram:

R2 and R4 are both within AS 65540, which indicates that they are in the same Autonomous System.

eBGP (External Border Gateway Protocol) is designed for routing between different ASes (inter-AS routing).

Since R2 and R4 are in the same AS, you would use:

OSPF or IS-IS (both interior gateway protocols -- IGPs)

Static routing is also valid between any two routers if manually configured

eBGP is invalid between routers in the same AS.

The correct protocol in that case would be iBGP (internal BGP) if BGP were to be used within the AS.

Therefore, the correct answer is: D. eBGP

Nokia IP Routing Fundamentals -- BGP vs IGP

Nokia SRA Guide -- AS Concepts and Protocol Suitability

RFC 4271 -- BGP Specification

Answer : D

In Nokia SR OS, the MD-CLI provides multiple configuration edit modes to allow different types of user interaction with the configuration system:

Private mode allows multiple users to create individual configuration candidates, which are then merged with the global candidate during commit.

Global mode enables multiple users to edit the same candidate configuration at the same time, with a shared commit session.

Read-only mode allows the user to view the configuration without making changes.

Exclusive mode restricts access to the global candidate configuration such that only one user at a time can enter and make changes. This prevents conflicts and is useful in environments where strict control over configuration changes is necessary.

Therefore, the correct answer is Exclusive mode, as it exclusively locks access to the global candidate for a single user.

Nokia SR OS MD-CLI User Guide -- Section: 'Configuration Edit Modes'

Nokia SRA Study Guide -- MD-CLI Configuration Concepts

Answer : B

The system interface in Nokia SR OS is a loopback-style logical interface that represents the router itself. It is used for:

Router ID assignment (if not manually set)

Source IP for control-plane protocols (OSPF, BGP)

Reachability testing

Important properties:

It is type loopback

It exists by default

If router ID is unset, it uses the system IP address

But the IP address on the system interface does not need to be /32

It can have other prefix lengths, especially in service provider scenarios.

Thus, Option B is FALSE.

Nokia SRA Study Guide -- Chapter: 'System Interface and Loopbacks'

Nokia SR OS Fundamentals Guide -- System IP Configuration Section

Answer : A

A broadcast domain is a logical division of a network in which all nodes can reach each other with broadcast frames (Layer 2). Devices within the same broadcast domain receive broadcast packets sent by others.

In the diagram:

Multiple users connect to hubs.

Hubs are Layer 1 devices and do not break broadcast domains. They simply replicate incoming electrical signals to all ports.

Hubs are then connected to switches.

Switches, unless VLANs are configured, forward broadcasts to all ports except the incoming one, effectively keeping all devices in the same broadcast domain.

The two switches are connected together without VLAN segmentation.

Therefore:

The entire LAN depicted is a single Layer 2 broadcast domain.

There are no routers or VLANs to break or separate the domain.

Correct answer: A. 1

Nokia IP Networking Fundamentals Study Guide -- Chapter: 'LAN Switching and Broadcast Domains'

Cisco and CompTIA Network+ materials on 'Hubs vs Switches vs Routers in Broadcast Domains'

Answer : C

The Shortest Path Tree (SPT) is calculated by Link-State routing protocols like OSPF and IS-IS using:

A complete map of the network topology.

Each router uses algorithms like Dijkstra's to compute the shortest paths to all destinations.

Option C is correct -- full network topology is used.

Option A refers to Distance Vector methods.

Option B and D are results of topology analysis but not the input used.

Nokia Routing Protocols Guide -- Section: ''SPT and Link-State Behavior''

RFC 2328 -- OSPF Specification

Answer : C

VPLS (Virtual Private LAN Service) is a Layer 2 VPN service that emulates a bridged Ethernet LAN across an MPLS/IP network.

Learns MAC addresses dynamically from:

SAPs (Service Access Points)

SDPs (Service Distribution Points)

Maintains a Forwarding Database (FDB) per VPLS instance.

For unknown MAC destinations, a VPLS floods the frame to all other sites -- just like a regular Ethernet switch.

Option C is FALSE -- VPLS does NOT discard unknown MACs; it floods them.

Nokia VPLS Services Guide -- Learning and Forwarding

Nokia SRA Study Guide -- VPLS Operation

Answer : A

The DHCP client/server exchange follows a specific four-step sequence known as DORA:

Discover -- Client broadcasts to find available DHCP servers.

Offer -- DHCP server responds with an IP address offer.

Request -- Client requests the offered IP.

Acknowledgement -- Server confirms the lease.

This ensures dynamic IP configuration and is used in enterprise and home networks.

Nokia IP Fundamentals Guide -- DHCP Protocol Operation

RFC 2131 -- Dynamic Host Configuration Protocol