Free Practice Questions for Nokia 4A0-115 Exam

Question 1

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.

Correct Answer: A. All VPLS instances must be configured on all PES regardless of whether they have a local host or not.

Explanation:

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.

Question 2

A. Proxy-ARP/ND is operational for a VPLS. Which of the following statements is FALSE?

BThe PE has proxy-ARP and dynamic-populate enabled for the VPLS.

CThe proxy-ARP table is populated by snooping IP packets received from remote PEs.

DWhen the PE learns a local host IP address, it adds an entry into its proxy-ARP table.

EThe PE advertises a MAC/IP route that includes the MAC and IP address of a local host.

Correct Answer: C. The proxy-ARP table is populated by snooping IP packets received from remote PEs.

Explanation:

When the PE learns a local host IP address, it does not add an entry into its proxy-ARP table. The proxy-ARP table is populated by snooping IP packets received from remote PEs. The PE advertises a MAC/IP route that includes the MAC and IP address of a local host.

Question 3

Which of the following statements about multi-homing for a Layer-2 service is TRUE?

AIn the single-active mode, the CE requires a LAG to be configured between the CE and all attached PEs.

BIn the single-active mode, the CE forwards traffic to all attached PES and receives traffic from a single PE.

CIn the all-active mode, all PES attached to a CE can forward traffic to and from the CE.

DThe Nokia 7750 SR supports a CE being multi-homed to a maximum of two PEs.

Correct Answer: C. In the all-active mode, all PES attached to a CE can forward traffic to and from the CE.

Explanation:

In the all-active mode, all PEs attached to a CE can forward traffic to and from the CE. This provides load balancing and redundancy for the CE.The CE does not require a LAG to be configured between the CE and all attached PEs1.

Verified Reference:Ethernet Virtual Private Networks (EVPNs)

Question 4

Which of the following statements about EVPN auto-discovery per EVPN instance (A-D per EVI) routes is FALSE?

AA PE uses the received updates to create aliasing lists to PES that are part of an all-active Ethernet segment.

BA PE advertises an A-D per EVI route for each operational service defined on an Ethernet segment.

CThe updates include an Ethernet tag ID that is set to zero.

DThe updates are used to discover all the PES associated with an Ethernet segment.

Correct Answer: B. A PE advertises an A-D per EVI route for each operational service defined on an Ethernet segment.

Explanation:

A PE does not advertise an A-D per EVI route for each operational service defined on an Ethernet segment. A PE advertises a single A-D per EVI route for all services defined on an Ethernet segment.

Question 5

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.

Correct Answer: D. EVPN-MPLS provides services over a simple IP network.

Explanation:

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 6

In the exhibit, the interface-less forwarding model is used for the Layer-3 EVPN service. Which of the following statements about traffic forwarding from Host 1 to Host 2 is FALSE?

APEI consults the FDB of RVPLS 1 and forwards the traffic to the local interface of VPRN 11.

BPEI encapsulates the packet with two labels: an outer transport label and an inner service label.

CPE2 inspects the service label and determines that it is associated with RVPLS 2.

DPE2 consults the FDB of RVPLS 2 and forwards the traffic to Host 2.

Correct Answer: B. PEI encapsulates the packet with two labels: an outer transport label and an inner service label.

Explanation:

PE1 does not encapsulate the packet with two labels: an outer transport label and an inner service label.PE1 encapsulates the packet with three labels: an outer transport label, a service label associated with VPRN 11, and a service label associated with RVPLS 11.

Verified Reference:Ethernet Virtual Private Networks (EVPNs)