OSPF Routing Essentials: Configuration & Troubleshooting

OSPF DR/BDR HQ Router Connection

Refer to the exhibit. Which statement describes the DR/BDR HQ router connection?

HQ is a DROTHER.

Frame Relay OSPF Point-to-Multipoint Characteristics

What two characteristics are associated with Frame Relay OSPF point-to-multipoint environments? (Choose two.)

• A DR is not elected.
• OSPF neighbor routers are statically defined.

OSPF Default Gateway Determination for R2

Refer to the exhibit. How was the default gateway entry for R2 determined in OSPF?

The default gateway entry for R2 was determined because the default-information originate command is applied on R1.

OSPF Requirement for Sharing Routing Information

What is always required for OSPF routers to share routing information?

For OSPF routers to share routing information, neighbor adjacencies are always required.

OSPF Lowest Cost Route from Host3 to Host1

Refer to the exhibit. A network administrator has implemented OSPF, and the network has converged. If all router interfaces are enabled and functional, what route will OSPF view as the lowest cost when moving frames from Host3 to Host1?

OSPF will view the lowest cost route from Host3 to Host1 as R3 to R2 to R1.

OSPF Router Configuration Example

Refer to the exhibit. How is a router configured for OSPF?

A router is configured for OSPF using the following commands:

router ospf 1
network 192.168.10.64 0.0.0.63 area 0
network 192.168.10.192 0.0.0.3 area 0

OSPF Network Statement for All Interfaces

Refer to the exhibit. Which network statement configures the home router to allow all its interfaces to participate in OSPF?

The network statement that configures the home router to allow all interfaces to participate in OSPF is:

network 10.8.0.0 0.3.255.255 area 0

OSPF DR and BDR Election Rules

Which statement is true regarding OSPF DR and BDR elections?

Regarding OSPF DR and BDR elections, the true statement is: Configuring the router with the highest priority wins the OSPF DR election.

OSPF Network Advertisement to Router1

Refer to the exhibit. The network administrator wants only the 172.16.32.0 network advertised to Router1. Which OSPF network command accomplishes this?

To advertise only the 172.16.32.0 network to Router1, the following OSPF network command is used:

Router2(config-router)# network 172.16.32.0 0.0.15.255 area 0

Link-State Routing Protocol Operations

Which two statements describe the operation of link-state routing protocols? (Choose two.)

• All routers in the same area have identical link-state databases when converged.

OSPF DR/BDR Status After Router Addition

Refer to the exhibit. Routers A, B, and C are part of an existing OSPF network. Router D was added to the network. All OSPF routers are running, and the identified priorities are applied to the interfaces. What is the DR/BDR status immediately after Router D is added to the existing network?

Immediately after Router D is added, the DR and BDR do not change until the next election.

OSPF DR/BDR Election Scenarios

Which two statements describe the use of OSPF DR/BDR elections? (Choose two.)

• Elections are required in broadcast multiaccess networks.
• Elections are sometimes required in NBMA networks.