OSPF (v2 and V3) CCIE-ENTERPRISE-INFRASTRUCTURE Practice Questions (Page 3)

Questions 11–15

1. 11expert · hard

   An OSPF network has multiple areas and an ASBR redistributing external routes. The engineer wants to reduce the number of external LSAs in the network and improve stability. The external routes are from contiguous subnets. What is the best approach?

   • ASummarize the external routes on the ABR using the area range command.
   • BIncrease the SPF throttling timers.
   • CSummarize the external routes on the ASBR using the summary-address command.
   • DUse a stub area to block external LSAs.
   Reveal Solution Discussion Select an answer first
2. 12expert · hard

   An OSPF network is experiencing slow convergence after a link failure. The engineer suspects that SPF calculations are taking too long due to the large number of routes. The network is stable most of the time, but during failures, CPU usage spikes. What is the most effective optimization to reduce SPF calculation time while maintaining fast convergence?

   • ADisable LSA throttling to allow faster flooding.
   • BIncrease the SPF hold time to 10 seconds.
   • CEnable incremental SPF (iSPF) to limit SPF calculations to affected areas.
   • DUse a single area to reduce SPF scope.
   Reveal Solution Discussion Select an answer first
4. 13expert · hard · select all that apply

   A network engineer is tuning OSPF for fast convergence on a critical link. The link is a point-to-point serial link. Which of the following configurations can help achieve sub-second convergence? (Select all that apply.)

   • AEnable LSA throttling with low initial delay.
   • BDisable OSPF on the interface.
   • CIncrease the retransmit interval.
   • DEnable BFD on the interface.
   • ESet the Hello interval to 1 second and Dead interval to 3 seconds.
   Check answers Discussion Select an answer first
5. 14application · medium

   An enterprise is migrating to dual-stack IPv4/IPv6 and wants to run OSPFv3 to carry both address families. The network has a backbone area 0 and several standard areas. The engineer needs to ensure that OSPFv3 advertises both IPv4 and IPv6 routes throughout the network. What is the correct configuration approach?

   • AConfigure OSPFv3 with the address-family ipv4 unicast and use the IPv4 address-family LSA types.
   • BEnable OSPFv3 with the address-family ipv4 and address-family ipv6 under the same OSPFv3 process.
   • CUse OSPFv3 only for IPv6 and rely on static routes for IPv4.
   • DRun separate OSPFv2 and OSPFv3 processes, one for IPv4 and one for IPv6.
   Reveal Solution Discussion Select an answer first
6. 15application · medium

   A service provider connects two customer routers over an Ethernet link that does not support broadcast (e.g., a non-broadcast multi-access link). The engineer needs to establish OSPF adjacency without relying on DR/BDR election. Which OSPF network type should be configured on the interface?

   • Abroadcast
   • Bpoint-to-multipoint
   • Cpoint-to-point
   • Dnon-broadcast
   Reveal Solution Discussion Select an answer first