Layer 3 VPN Concepts and Architecture JN0-664 Practice Questions (Page 2)

Questions 6–10

1. 6foundation · easy

   Why is the VPN-IPv4 address format necessary in a Layer 3 VPN?

   • ATo allow the provider core to route customer traffic using standard IPv4 routing.
   • BTo enable the use of IPv6 addresses in the customer network.
   • CTo reduce the size of the BGP table by aggregating customer routes.
   • DTo ensure that customer IPv4 prefixes are unique in the provider's BGP table, even if they overlap.
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2. 7application · medium

   A network engineer is examining the MP-BGP table on a PE router and sees the following entry: '64496:100:10.10.10.0/24'. What does the '64496:100' portion of this prefix represent?

   • AThe AS number of the customer, which is used to identify the VPN
   • BThe route distinguisher, which is an 8-byte value used to make the IPv4 prefix unique across different VPNs
   • CThe MPLS label assigned to the route by the advertising PE
   • DThe route target, which is used to control the import and export of the route into VRFs
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4. 8foundation · easy

   What is the function of a route target (RT) in a Layer 3 VPN?

   • ATo control the import and export of VPN routes into VRF tables.
   • BTo specify the MPLS label used for forwarding VPN traffic.
   • CTo identify the next-hop PE router for a VPN route.
   • DTo make customer prefixes unique in the provider's BGP table.
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5. 9application · medium

   A service provider is adding a new customer to an existing Layer 3 VPN infrastructure. The new customer has two sites that need to communicate. The provider wants to minimize the configuration changes on the existing PE routers. What is the most efficient way to provision this new customer?

   • AAdd the new customer's sites to an existing VRF and configure a new route target for the new sites
   • BConfigure the new customer's sites to use the same route distinguisher as an existing customer
   • CCreate a new VRF on the PE routers connected to the new customer's sites, assign a unique route distinguisher, and configure route targets for the new VRF
   • DUse a separate routing instance on the P routers for the new customer
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6. 10foundation · medium

   In a Layer 3 VPN, which statement correctly describes how VRF import and export policies use route targets to control route distribution?

   • AThe import policy attaches route targets to routes received from other PEs, while the export policy uses route targets to filter which routes are placed into the local VRF.
   • BRoute targets are used only in the export policy to tag routes, while the import policy relies solely on the route distinguisher to determine VRF membership.
   • CBoth import and export policies use the same route target list, which is configured on the PE router and applied to all VRFs to ensure consistent route exchange.
   • DThe export policy attaches one or more route targets to routes being advertised from the local VRF, while the import policy determines which received VPN routes are placed into the local VRF based on matching route targets.
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