Nokia 4A0-100 Exam Questions Instant Access

Question 1

Refer to the exhibit.

An Ethernet Local Area Network (LAN) consists of the components shown in the diagram. Assuming there are no VLANs, how many broadcast domains are on this LAN?

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'

Question 2

In an MPLS network, which device is responsible for taking an unlabeled packet and encapsulating it with an MPLS label?

AIngress Label Edge Router

BEgress Label Edge Router

CLabel Switching Router

DNext-hop Router

Answer : A

The Ingress Label Edge Router (LER) is the first router that:

Receives an unlabeled IP packet.

Applies an MPLS label based on its forwarding decision.

Forwards it into the MPLS core.

Option A is correct -- Ingress LER does MPLS label push.

Option B (Egress LER) -- removes labels at the end of the path.

Option C (LSR) -- switches labels, but doesn't push them onto unlabeled packets.

Option D -- is not a specific MPLS role.

Nokia IP/MPLS Fundamentals Guide -- Label Operations

RFC 3031 -- MPLS Architecture

Question 3

Which of the following types of information is used to calculate the Shortest Path Tree (SPT)?

ACopies of the neighbors' routing tables

BHop count to each potential destination

CNetwork topology

DIP reachability

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

Question 4

Which of the MPLS routers is responsible for pushing new labels for LSP A and LSP B?

ARouter R1 pushes labels for both LSP A and LSP B.

BRouter R4 pushes labels for both LSP A and LSP B.

CRouter R1 pushes labels for LSP A, while router R4 pushes labels for LSP B.

DRouter R4 pushes labels for LSP A, while router R1 pushes labels for LSP B.

Answer : C

Nokia MPLS Fundamentals Guide -- Chapter: ''Label Operations (Push, Swap, Pop)''

Nokia SRA Study Guide -- Ingress/Egress LER roles in MPLS

Question 5

Which of the following is a characteristic of Link State protocols?

ARouters send a copy of their entire routing table to their neighbors.

BRouters send periodic routing table updates to the entire network.

CRouters know the entire network topology.

DRouters use hop-count to calculate their routing tables.

Answer : C

Link-State routing protocols (e.g., OSPF, IS-IS) operate by:

Each router flooding link-state advertisements (LSAs) throughout the network.

Every router constructs a complete map of the network topology.

Then each router runs the SPF algorithm to compute optimal paths.

Option C is correct -- routers know the entire network topology.

Option A is Distance Vector behavior (e.g., RIP).

Option B is not efficient or accurate for Link-State.

Option D -- hop-count is used in Distance Vector (e.g., RIP).

Nokia SRA Study Guide -- Chapter: ''OSPF and IS-IS Concepts''

RFC 2328 -- OSPF Link-State Overview

Question 6

Which compact flash on a control processing module (CPM) of a Nokia 7750 SR stores the runtime software image and the configuration file?

ACF1

BCF2

CCF3

DBoth CF1 and CF2

Answer : C

Question 7

Which of the following is a characteristic of a static route?

AExchanges routes with neighboring routers periodically.

BCan only be used for routing within an autonomous system.

CUses a hop-count metric to determine the best route to a network.

DExplicitly defines the next-hop based on operator input.

Answer : D

A static route is a manually configured route added by a network administrator. It does not rely on dynamic routing protocols or metrics.

It does not exchange routes with other routers (A -- false).

It can be used both within or across ASes (B -- false).

It does not use metrics like hop count (C -- false).

Option D is correct -- the operator explicitly defines the next-hop IP or egress interface manually.

Static routes are often used for:

Default routing

Backup routing

Simple or small networks

Nokia IP Fundamentals -- Chapter: ''Static vs Dynamic Routing''

Nokia IP Networks and Services Fundamentals 4A0-100 Exam Questions