4A0-115

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.
A . The MPLS label 524284 presented indicates the service label value that the neighbor 10.10.10.2 uses to forward BUM traffic to PEI.
B . When forwarding BUM traffic, the local PE uses an MPLS transport tunnel towards the advertising neighbor.
C . The IMET route is imported by a local VPLS configured with a route-target value of 65100:10.

View Answer

Answer: A

Explanation:

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.

What are EVPN inclusive multicast Ethernet tag (IMET) routes used for?
A . To advertise the MAC or MAC/IP addresses of locally-learned hosts
B . To advertise the redundancy mode of a local Ethernet segment
C . To discover all PES participating in the same VPIS service
D . To discover all PES attached to the same Ethernet segment

View Answer

Answer: C

Explanation:

EVPN inclusive multicast Ethernet tag (IMET) routes are used to discover all PEs participating in the same VPIS service. These routes are also used to build the flooding list for BUM traffic.

In the exhibit,

MACI moves from PEI to PE2.

Which of the following actions related to this MAC address mobility is performed?
A . CEI generates an update message to PEI withdrawing its MAC.
B . PEI generates an update message to remote PES identifying the new location of CEI.
C . PE2 advertises a MAC/IP route for MACI with a sequence number higher than that received from PEI.
D . PE3 waits to receive a data packet from CEI to update its FDB entry for MACI.

View Answer

Answer: C

Explanation:

PE2 advertises a MAC/IP route for MAC1 with a sequence number higher than that received from PE1. This indicates that MAC1 has moved from PE1 to PE2 and triggers a MAC withdrawal message from PE1 to remote PEs. CE1 does not generate an update message to PE1 withdrawing its MAC, nor does PE1 generate an update message to remote PEs identifying the new location of CE11.

Reference: Ethernet Virtual Private Networks (EVPNs)

Which of the following statements about PE-to-PE MAC address advertisement is FALSE?
A . The service distinguisher (label or VNI) is advertised with the MAC/IP EVPN update.
B . Route targets are used to uniquely identify routes between EVIS in the case of MAC address overlaps.
C . A PE uses a single MP-BGP session with a remote peer to exchange the routes for all EVIs.
D . A PE advertises locally-learned MAC addresses to remote PES using EVPN type-2 routes.

View Answer

Answer: B

Explanation:

Route targets are not used to uniquely identify routes between EVIs in the case of MAC address overlaps. Route targets are used to control the import and export of routes between different EVIs or VRFs. The service distinguisher (label or VNI) is used to uniquely identify each service1.

Reference: Ethernet Virtual Private Networks (EVPNs)

Which of the following statements about EVPN Layer-3 services that utilize the interface-full model is TRUE?
A . EVPN MAC/IP routes are used to advertise the IP prefixes of subnets attached to a VPRN.
B . VPRN instances are interconnected using a supplementary broadcast domain (SBD) VPLS.
C . Intra-subnet traffic is carried over the tunnels provided by the SBD VPLS.
D . The MAC/IP routing information is used to populate the VPRN routing table at the remote PEs.

View Answer

Answer: C

Explanation:

In the interface-full model, VPRN instances are interconnected using a supplementary broadcast domain (SBD) VPLS. Intra-subnet traffic is carried over the tunnels provided by the SBD VPLS. The MAC/IP routing information is not used to populate the VPRN routing table at the remote PEs, but rather to populate the FDB of the SBD VPLS2.

Reference: Nokia Ethernet Virtual Private Network Services Course | Nokia