Designated Router Operations JN0-664 Practice Questions (Page 1)

Questions 1–5

1. 1foundation · easy

   What is the primary benefit of using a DR/BDR on a broadcast multi-access OSPF network?

   • AIt reduces the number of OSPF adjacencies required
   • BIt increases the speed of SPF calculations
   • CIt eliminates the need for hello packets
   • DIt allows OSPF to run over non-broadcast networks
   Reveal Solution Discussion Select an answer first
2. 2foundation · easy

   How does an OSPF router detect that the Designated Router (DR) on a broadcast segment has failed?

   • AIt receives a notification from the BDR that the DR is down
   • BIt stops receiving hello packets from the DR within the dead interval
   • CIt receives a route withdrawal from the DR's neighbors
   • DIt receives a link-state advertisement (LSA) from the DR indicating shutdown
   Reveal Solution Discussion Select an answer first
4. 3foundation · easy

   On a broadcast multi-access network, which two values are used to determine the Designated Router (DR) election outcome?

   • ARouter ID and link-state age
   • BInterface priority and cost
   • CInterface priority and router ID
   • DRouter ID and area ID
   Reveal Solution Discussion Select an answer first
5. 4foundation · medium

   On an OSPF broadcast multi-access network, which statement correctly describes how link-state advertisements (LSAs) are flooded and how databases are synchronized through the designated router (DR)?

   • ALSAs are flooded to the DR, which then sends them to the network's multicast address 224.0.0.6 for all routers to receive.
   • BEvery router floods its LSAs directly to every other router on the segment using the AllSPFRouters multicast address.
   • CAll routers send their LSAs to the DR and backup designated router (BDR), which then flood them to all other routers on the segment.
   • DRouters send their LSAs only to the DR, which then forwards them to the BDR for flooding to the rest of the segment.
   Reveal Solution Discussion Select an answer first
6. 5expert · medium

   A service provider has an OSPF broadcast segment with a DR, a BDR, and four DROTHER routers. The DR router experiences a hardware failure and goes offline. How does OSPF recover from this failure, and what is the impact on network convergence?

   • AThe DR failure causes all adjacencies on the segment to be torn down, and a full re-election process occurs, causing significant convergence delay.
   • BAll DROTHER routers detect the DR failure and immediately elect a new DR from among themselves; the BDR remains in its role.
   • CThe BDR immediately becomes the new DR, and a new BDR is elected from the DROTHER routers; convergence is fast because the BDR already has full adjacencies.
   • DThe router with the highest router ID among the DROTHER routers becomes the new DR, and the BDR remains as BDR.
   Reveal Solution Discussion Select an answer first