Multicast VPN Configuration | Cisco CCIE Service Provider Written Exam

VRF Definition ABC Configuration

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Question

Based on the following configuration: vrf definition ABC rd 10.0.0.1:1000 ! address-family ipv4 route-target export 1:1 route-target import 1:1 mdt default 232.0.0.1 Which two statements about multicast VPN configuration are true? (Choose two.)

Answers

A. The multicast tree is created based only on the existence of active sources or receivers behind PEs in the ABC VR.

B. The service provider core network is required to support SSM.

C. Multicast needs to be enabled only on ABC VRF and is tunneled to participating PE routers in the ABC VR.

D. The SP core network is required in order to enable the BGP Multicast Address Family on all peering.

E. Multicast is required for the core network in addition to the ABC VR.

F. The multicast tree exists regardless of whether there are any active sources or receivers in the ABC VR.

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Explanations

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A. B. C. D. E. F.

EF.

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The given configuration defines a Virtual Routing and Forwarding (VRF) instance named "ABC" with route distinguisher (RD) 10.0.0.1:1000. The configuration also specifies that multicast traffic should be sent to the multicast group 232.0.0.1, and route-target import and export settings for IPv4 address family have been set to 1:1.

Based on this configuration, the following statements about multicast VPN configuration are true:

A. The multicast tree is created based only on the existence of active sources or receivers behind PEs in the ABC VR.

This statement is true. Multicast traffic is delivered only to the PEs that have active multicast sources or receivers within the ABC VRF. The multicast tree is not created if there are no active sources or receivers within the ABC VRF.

B. The service provider core network is required to support SSM.

This statement is not necessarily true. The configuration does not specify the use of Source-Specific Multicast (SSM). The service provider core network may support either SSM or Any-Source Multicast (ASM).

C. Multicast needs to be enabled only on ABC VRF and is tunneled to participating PE routers in the ABC VR.

This statement is true. The configuration specifies that multicast traffic should be sent to the multicast group 232.0.0.1, and it will be tunneled to the participating PE routers in the ABC VRF. Multicast does not need to be enabled on the service provider core network.

D. The SP core network is required in order to enable the BGP Multicast Address Family on all peering.

This statement is not necessarily true. The configuration does not specify the use of BGP Multicast Address Family. If BGP Multicast Address Family is used, it will be enabled on the peering routers that participate in the ABC VRF.

E. Multicast is required for the core network in addition to the ABC VR.

This statement is not true. Multicast is not required for the service provider core network, as multicast traffic will be tunneled to the participating PE routers in the ABC VRF.

F. The multicast tree exists regardless of whether there are any active sources or receivers in the ABC VR.

This statement is false. The multicast tree is created only when there are active sources or receivers in the ABC VRF. If there are no active sources or receivers, the multicast tree will not be created.

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