Nokia 4A0-112 Exam Questions Instant Access

Question 1

Consider the exhibit.

All routers are running IS-IS with IPv6 support enabled. Based on the topology shown, and the route tables of routers R3 and R4, which of the following statements is TRUE?

AThere is no route leaking configured on router R1 or router R2.

BRoute leaking is configured on router R1 but not on router R2.

CRoute leaking is configured on router R2 but not on router R1.

DRoute leaking is configured on both routers R1 and R2.

Answer : D

Based on the IPv6 route table output for R3 and R4, we can see that the routers have remote routes listed as 'Remote ISIS', indicating that the route is being advertised from a different area (area 49.01 or 49.02). This is a sign of route leaking, where routes from one area are being shared across areas.

The routes from R3 (level-1 router) are being advertised to R4 (level-1 router), and vice versa, with ISIS as the protocol. This implies that there is route leaking configured to allow information to pass between areas.

Question 2

Refer to the exhibit.

All routers in the diagram are running an interior gateway protocol (IGP) and have been configured with an ECMP value of 4. Router R5 advertises the prefix 192.168.3.0/24 using the IGP. Assuming all links have the same cost, how many entries for prefix 192.168.3.0/24 will be in router R3's routing table?

Answer : D

In this scenario, the routers are configured with an Equal-Cost Multi-Path (ECMP) value of 4, meaning they can utilize up to 4 equal-cost paths to reach a destination. Since Router R5 is advertising the 192.168.3.0/24 prefix and all links have the same cost, router R3 will receive multiple routes to reach this destination.

Given that all the routers (R1, R2, R3, R4, and R5) are connected in a way that can support multiple equal-cost paths, and assuming ECMP is set to 4, the routing table on Router R3 will have up to 4 entries for the prefix 192.168.3.0/24.

Thus, Router R3's routing table will contain 4 entries for the prefix 192.168.3.0/24.

Question 3

Refer to the exhibit.

A static route has been configured on router R1 to reach the PC at 139.120.121.2.

What might be causing the ping to fail?

ARouter R2 needs a static route to the PC.

BRouter R1 needs a static route to router R2.

CThe configured next hop does not belong to a subnet adjacent to R1.

DThe configured static route needs to be a default route.

Answer : C

In the configuration on router R1, the static route is defined with the next-hop IP address of 139.120.121.1.

However, the next-hop IP address 139.120.121.1 does not belong to the same subnet as the directly connected interface on R1, which is 172.31.1.1/30. For the static route to work properly, the next-hop IP address must be reachable via a directly connected interface, meaning it must be within the same subnet.

Therefore, this mismatch in subnet adjacency is likely causing the failure to reach the destination (139.120.121.2).

Question 4

Which of the following is NOT a function of the control plane a router?

ATo exchange signaling messages with other routers.

BTo determine the best way to forward packets.

CTo establish routing paths to deliver packets from source to destination and to reestablish them in case of failure.

DTo utilize the forwarding tables to forward data packets towards their destination.

Answer : D

The data plane (or forwarding plane) is responsible for actually forwarding the data packets. It uses the information stored in the forwarding table to determine how to move packets from one interface to another toward their destination.

Question 5

A router running a link-state routing protocol detects that one of its neighbors is no longer connected to it. The router generates a new link-state advertisement to inform other routers of the topology change. Which of the following is NOT an action that is triggered by this event?

AIf a router receives the new link-state advertisement, it acknowledges it, stores it, and forwards it to its own neighbors.

BIf a router receives multiple copies of the new link-state advertisement, it will simply ignore all copies received after the first one.

CEvery router that receives the new link-state advertisement updates its age field before forwarding it.

DEvery router that receives the new link-state advertisement runs the SPF algorithm to recalculate its shortest-path tree and its forwarding database.

Answer : C

When a router receives a link-state advertisement (LSA), it does not update the age field before forwarding it. The age field in an LSA is typically updated by the originating router or during the process of forwarding the LSA within the network. Routers do not modify the age field upon receiving and forwarding an LSA.

Question 6

Which of the following is NOT a required configuration step to successfully run IS-IS on a router?

AThe router needs to be associated with an IS-IS area ID.

BLayer-3 interfaces that will participate in IS-IS need to be identified.

CA reference bandwidth needs to be configured to calculate link costs.

DThe IS-IS context needs to be enabled.

Answer : C

While configuring a reference bandwidth (which is used to calculate link costs) can be useful, it is not strictly required for IS-IS to run. IS-IS uses default bandwidth values to calculate costs, and it can function without explicitly configuring a reference bandwidth.

Question 7

Refer to the exhibit.

In the diagram, all routers are using IS-IS as their routing protocol. The number next to each link is its metric value.

What path will traffic follow from router R6 to router R3, and from router R3 to router R6?

ARouter R6 to router R3 will follow (R6-R5-R2-R3). Router R3 to router R6 will follow (R3-R2-R5-R6).

BRouter R6 to router R3 will follow (R6-R5-R2-R3). Router R3 to router R6 will follow (R3-R4-R2-R5-R6).

CRouter R6 to router R3 will follow (R6-R5-R2-R3). Router R3 to router R6 will follow (R3-R4-R7-R5-R6).

DRouter R6 to router R3 will follow (R6-R5-R7-R4-R3). Router R3 to router R6 will follow (R3-R4-R7-R5-R6).

Answer : A

The metric values between the routers dictate the routing paths, and IS-IS will calculate the shortest path based on these values.

R6 to R3: The path from R6 to R3 will go through R5 and R2, as this route has the least cumulative metric (10 + 10 + 15 = 35).

R3 to R6: The reverse path from R3 to R6 will follow R3 R2 R5 R6 because this route is also the shortest with a total metric of 10 + 10 + 10 = 30.

Nokia IS-IS Routing Protocol 4A0-112 Exam Questions