Nokia 4A0-115 Exam Questions Instant Access

Question 1

In the exhibit, the default algorithm is used to elect the designated forwarder (DF) on ESI 1. Which PE is elected as DF for VPLS 10?

APEI

BPE2

CPE3

DPE4

Answer : B

PE2 is elected as DF for VPLS 10. The default algorithm uses the lowest IP address of the PEs attached to the same Ethernet segment as the tie-breaker criterion. PE2 has the lowest IP address among PE1, PE2, and PE3.

Question 2

In the exhibit, VPWS 4 enables communications between CEI and CE2. Which of the following statements regarding the operation of VPWS 4 is FALSE?

APEI advertises an auto-discovery per EVPN instance (A-D per EVI) route to PE3 as soon as the SAP becomes operationally

BPE3 advertises an IMET route to PEI as soon as VPWS 4 is administratively enabled.

CPEI and PE3 exchange their service labels using A-D per EVI routes.

DPE3 and PE4 exchange their service labels over an established targeted LDP session.

Answer : C

PE1 and PE3 do not exchange their service labels using A-D per EVI routes.PE1 and PE3 exchange their service labels using MAC routes, which are advertised when their local ACs become operationally UP1.

Verified Reference:Ethernet Virtual Private Networks (EVPNs)

Question 3

Which of the following statements about the EVPN data plane is FALSE?

AEVPN allows a service provider to deliver multiple services over a single core network.

BThe customer data is encapsulated and then tunneled between the PE routers.

CEVPN-MPLS encapsulated data has a label that uniquely identifies each service.

DEVPN-MPLS provides services over a simple IP network.

Answer : D

EVPN-MPLS provides services over an MPLS network, not a simple IP network.The customer data is encapsulated with an MPLS label that identifies the service and then tunneled between the PE routers using MPLS LSPs1.

Verified Reference:Ethernet Virtual Private Networks (EVPNs)

Question 4

Based on the exhibit below, which of the following statements is FALSE?

When forwarding BUM traffic, the local PE must replicate the traffic and send it as unicast to the advertising neighbor.

AThe MPLS label 524284 presented indicates the service label value that the neighbor 10.10.10.2 uses to forward BUM traffic to PEI.

BWhen forwarding BUM traffic, the local PE uses an MPLS transport tunnel towards the advertising neighbor.

CThe IMET route is imported by a local VPLS configured with a route-target value of 65100:10.

Answer : A

When forwarding BUM traffic, the local PE does not replicate the traffic and send it as unicast to the advertising neighbor. Instead, the local PE uses an MPLS transport tunnel towards the advertising neighbor and sends the traffic with an MPLS label that indicates the service.

Question 5

Based upon the exhibit,

which of the following statements about the forwarding of BUM traffic is FALSE?

APE3 replicates the traffic and sends it to all PES in its VPLS I flooding list.

BPE3 adds an ESI label to packets forwarded to PEI because PEI is connected to the same Ethernet segment.

CPEI forwards the traffic received from PE3 to CEI, and CEI discards it based upon the ESI label.

DPE2 decapsulates the packets received from PE3 and forwards the frames to CE2.

Answer : B

PE3 does not add an ESI label to packets forwarded to PE1 because PE1 is connected to the same Ethernet segment.PE3 adds an ESI label only to packets forwarded to PEs that are not connected to the same Ethernet segment, such as PE21.

Verified Reference:Ethernet Virtual Private Networks (EVPNs)

Question 6

Which of the following statements about the EVPN Layer 2 Attributes extended community is FALSE?

AIt is advertised with the auto-discovery per EVPN instance (A-D per EVI) route.

BIt is applicable to EVPN VPLS services.

CIt specifies the service maximum transmission unit (MTU).

DIt specifies a P flag that indicates whether the advertising PE is a primary PE.

Answer : B

The EVPN Layer 2 Attributes extended community is not applicable to EVPN VPLS services.It is applicable to EVPN VPWS services, where it carries information such as the tag ID and the service MTU1.

Verified Reference:Ethernet Virtual Private Networks (EVPNs)

Question 7

Which of the following statements does NOT describe the operation of the Layer-3 EVPN asymmetric forwarding model?

AAll VPLS instances must be configured on all PES regardless of whether they have a local host or not.

BEVPN IP-Prefix routes are used to populate the VPRN VRF tables.

CThe egress PE does not perform any Layer-3 route look up to forward traffic.

DThe ingress PE performs both Layer-2 and Layer-3 look ups when forwarding traffic between subnets.

Answer : A

All VPLS instances do not need to be configured on all PEs regardless of whether they have a local host or not. Only the VPRN instance needs to be configured on all PEs, while the VPLS instances are configured only on PEs that have a local host attached to them.

Nokia Ethernet Virtual Private Network Services 4A0-115 Exam Questions