Cisco CCNA Single-Area OSPFv2 Configuration Questions and Answers

Question 1

A network engineer configures a Cisco router for single-area OSPFv2.
The router has three active interfaces: Loopback0 (10.0.0.1/32), GigabitEthernet0/0 (192.168.1.1/24), and GigabitEthernet0/1 (172.16.1.1/24).
The OSPF process is started, but the `router-id` command is NOT used.
Which IP address will OSPF select as the router ID?

Accepted Answer

10.0.0.1

Answer

192.168.1.1

Answer

172.16.1.1

Answer

The OSPF process will fail to start without a manual router-id.

Question 2

An administrator needs to enable OSPF on an interface with the IP address 192.168.10.65/27. Which of the following `network` commands will correctly and most precisely enable OSPF only on this specific interface?

Accepted Answer

network 192.168.10.65 0.0.0.0 area 0

Answer

network 192.168.10.64 0.0.0.31 area 0

Answer

network 192.168.10.65 255.255.255.224 area 0

Answer

network 192.168.10.0 0.0.0.255 area 0

Question 3

A network administrator issues the `passive-interface default` command under the OSPF process. What is the effect of this command?

Accepted Answer

It stops OSPF from forming adjacencies on any interface.

Answer

It prevents all interfaces from being advertised in OSPF.

Answer

It sets the OSPF cost to the default value on all interfaces.

Answer

It enables OSPF on all interfaces using default timers.

Question 4

Two OSPF routers are connected via a FastEthernet link (100 Mbps) but are failing to form a full adjacency, remaining in the 2-WAY state. Both routers are on the same subnet (10.1.1.0/30) and in the same area (Area 0). Which of the following is a valid reason for this issue on a broadcast network type like Ethernet?

Accepted Answer

The OSPF priority on both routers is set to 0.

Answer

The OSPF process IDs do not match.

Answer

One router is a DR, and the other is a DROTHER.

Answer

The Hello and Dead timers are mismatched.

Question 5

A company's network includes links with speeds of 1 Gbps and 10 Gbps. A network engineer notices that OSPF is treating both links as having the same cost. What command should be used within the OSPF routing process to ensure OSPF calculates a more granular and accurate cost for these high-speed links?

Accepted Answer

auto-cost reference-bandwidth 10000

Answer

ip ospf cost 10

Answer

bandwidth 10000

Answer

speed auto 10000

Question 6

To establish an OSPFv2 neighbor adjacency, which of the following parameters must be identical on two directly connected routers?

Accepted Answer

Area ID and Subnet Mask

Answer

Router ID

Answer

Process ID

Answer

OSPF Interface Priority