300-515 Implementing Cisco Service Provider VPN Services (SPVI) Practice Questions
Prepare for 300-515 with more than an answer.
- 1
While configuring a Multicast VPN (mVPN), a network administrator wants to optimize bandwidth usage for high-volume multicast streams. They decide to implement a configuration where specific high-bandwidth groups switch from the shared P-multicast tree to a dedicated tree for that stream. Which mechanism implements this behavior?
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Correct answer: D
The Data MDT (Data Multicast Distribution Tree) is a mechanism in mVPN where high-bandwidth traffic is switched from the Default MDT (which floods to all PEs) to a dedicated Data MDT that only includes PEs with interested receivers, optimizing core bandwidth.
- 2
A network consultant is designing an EVPN solution for a Data Center Interconnect (DCI). The requirement is to support multihoming where a CE device connects to two PE routers using LACP. Traffic must be load-balanced across both links (All-Active mode). Which EVPN parameter is critical for identifying this specific Ethernet segment across the PE routers?
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Correct answer: A
The Ethernet Segment Identifier (ESI) is a unique non-zero 10-byte value that identifies the Ethernet segment. PE routers connected to the same multihomed CE must be configured with the same ESI for that segment to enable All-Active multihoming and DF election.
- 3
A service provider is configuring a 6VPE (IPv6 VPN Provider Edge) service. The core network is IPv4-only and uses MPLS. Which specific BGP address family must be configured on the PE routers to exchange the customer's IPv6 prefixes with the correct VPN labels?
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Correct answer: B
For 6VPE, the PE routers use the
address-family vpnv6 unicast(orvpnv6) to exchange IPv6 prefixes that are made unique by the Route Distinguisher (RD). This address family carries the IPv6 prefix, the RD, and the VPN label over the MP-BGP session. - 4
A network engineer is troubleshooting an issue with an E-Tree service implemented using EVPN. In this topology, traffic from 'Leaf' sites should only communicate with 'Root' sites and not with other 'Leaf' sites. Which BGP Extended Community is used in EVPN to signal the Leaf/Root role of an Ethernet Segment to enforce this split-horizon behavior?
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Correct answer: A
The E-Tree Extended Community is used in EVPN to designate an attachment circuit as either Root or Leaf. When a PE receives a route with the Leaf indication, it ensures that traffic from that source is not forwarded to other Leaf attachment circuits, enforcing the E-Tree forwarding rules.
- 5
A service provider needs to verify the Label Switched Path (LSP) for a specific L3VPN prefix to troubleshoot a blackhole issue. They want to trace the path across the MPLS core, verifying the label swap operations at each hop. Which command should be used to perform this verification specifically for a VPNv4 prefix?
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Correct answer: D
The command
traceroute vrf(ortraceroute mpls vpnon some platforms) initiates an LSP trace that encapsulates the probe with the correct VPN label and Transport label, allowing verification of the actual forwarding path taken by customer traffic within that VRF. - 6
Which utility can you use to validate an LSP in an MPLS environment? A.uRPFB.MPLS LSP pingC.loggingD.RSVP
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Correct answer: B
- 7
What is the primary function of a VRF on a router? A.It enables the router to support multiple separate routing tables, which allows the device to handle overlapping IP addresses.B.It enables a router to run BGP and a distance vector routing protocol at the same time, which allows it to serve as a VPN endpoint between remote sites.C.It enables a router to configure VLANs locally, which provides segregation between networks.D.It enables the router to provide faster switching through the network by using labels to identify the input and output interfaces for neighbor routers.
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Correct answer: A
- 8
Which two statements describe primary differences between MPLS Layer 2 and Layer 3 VPNs? (Choose two.) A.Layer 2 VPNs use IPsec tunneling, but Layer 3 VPNs use L2TPv3 tunneling.B.Layer 2 VPNs use AToM, but Layer 3 VPNs use MPLS/BGP.C.Layer 2 VPNs use BGP, but Layer 3 VPNs use VPLS.D.Layer 2 VPNs use L2TPv3 tunneling, but Layer 3 VPNs use GRE tunneling.E.Layer 2 VPNs use IPsec tunneling, but Layer 3 VPNs use pseudowires to provide tunneling.
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Correct answer: B, D
