Objective 3.4
200-301Configure and verify single area OSPFv2.
Objective 3.4 sits in IP Connectivity, which carries 25% of the CCNA exam. The questions below are original, written from the official objective title above, and each explanation cites the Cisco page it rests on.
Objective title verbatim from the official objectives. Cisco exam page ↗
A worked example
Shown solved, with the whole explanation open: this is what every question here carries.
An engineer starts an OSPF process on this router and enters no router-id command.
Device# show ip interface briefInterface IP-Address OK? Method Status ProtocolGigabitEthernet1/0/1 10.1.1.1 YES manual up upGigabitEthernet1/0/2 172.16.5.1 YES manual up upLoopback0 192.168.10.1 YES manual up upLoopback1 192.168.9.1 YES manual up upWhich address becomes the router ID?
Correct.
Checked against cisco.com, August 2026Concept
A router ID has to stay fixed, as losing it forces the process to recalculate and reflood everything it knows. The selection therefore favors the one kind of interface that cannot go down, and only falls back to physical addressing when none exists.
Why C
Two loopbacks are present, so the physical interfaces are out of the running whatever their addressing. Between the two loopbacks the higher numeric address is taken, and 192.168.10.1 is higher than 192.168.9.1.
Source
Cisco: Configuring OSPF, Loopback Interfaces, checked August 2026If a loopback interface is configured with an IP address, OSPF uses this IP address as its router ID, even if other interfaces have higher IP addresses. Because loopback interfaces never fail, this provides greater stability. OSPF automatically prefers a loopback interface over other interfaces, and it chooses the highest IP address among all loopback interfaces.
Now you: objective 3.4 questions
No account needed. The explanation opens when you answer.
Sample question 1 of 3
A candidate notices that three OSPF entries learned in three different ways all carry the same first bracket value.
O 10.20.0.0/16 [110/12] via 10.0.0.2, 00:41:02, GigabitEthernet1/0/1O IA 10.30.0.0/16 [110/74] via 10.0.0.2, 00:40:58, GigabitEthernet1/0/1O E2 10.40.0.0/16 [110/20] via 10.0.0.2, 00:12:11, GigabitEthernet1/0/1What is that 110?
Sample question 2 of 3
R1 and R2 sit on one link and never reach full adjacency.
R1 configurationrouter ospf 1 network 10.0.0.0 0.0.0.3 area 0interface GigabitEthernet1/0/1 ip address 10.0.0.1 255.255.255.252 ip ospf hello-interval 5 R2 configurationrouter ospf 2 network 10.0.0.0 0.0.0.3 area 0interface GigabitEthernet1/0/1 ip address 10.0.0.2 255.255.255.252 ip ospf hello-interval 10Which difference explains it?
Sample question 3 of 3
An engineer adds network 10.1.1.0 0.0.0.255 area 0 under an OSPF process. What does that statement settle?
That’s 3 of the full CCNA bank.
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Continue practicingRead the sources
These are the official pages the questions above cite. Reading them is studying the objective from the primary source, which is what the explanations point you toward anyway.