CCNA IP Routing Practice Question
Which OSPF network type on Ethernet performs a DR and BDR election by default?
⚠ Common exam trap
A frequent exam trap is selecting point-to-point or point-to-multipoint nonbroadcast as the network type that performs DR/BDR elections. Candidates often assume any multi-router link requires DR/BDR, but OSPF only elects DR/BDR on broadcast and NBMA networks. Point-to-point links connect exactly two routers and do not need DR/BDR, while point-to-multipoint nonbroadcast requires manual neighbor configuration and does not elect DR/BDR by default. Misunderstanding these distinctions leads to incorrect answers. Remember, Ethernet interfaces default to broadcast network type, which triggers DR/BDR elections automatically.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Broadcast
Broadcast multiaccess networks such as Ethernet elect a DR and BDR by default.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Point-to-point
Why it's wrong here
A point-to-point network type applies to serial links or Ethernet links configured explicitly as point-to-point, where exactly two routers are connected. Because only two neighbors exist on the link, there is no need for a DR or BDR; the two routers simply form a full adjacency directly. Electing a DR would only add unnecessary protocol overhead and complexity.
When this WOULD be correct
If the question were to ask about OSPF network types that do not require DR and BDR elections, such as in a scenario involving a direct link between two routers, then 'Point-to-point' would be the correct answer.
- ✓
Broadcast
Why this is correct
On Ethernet segments, OSPF automatically defaults to the broadcast network type. This type relies on multicast hello packets to 224.0.0.5 and elects a Designated Router (DR) and Backup Designated Router (BDR) to minimize the number of adjacencies and reduce LSA flooding on the multi-access link. Therefore, broadcast is the correct network type where DR/BDR election occurs.
- ✗
Point-to-multipoint nonbroadcast
Why it's wrong here
Point-to-multipoint nonbroadcast is used for hub-and-spoke networks over nonbroadcast multi-access (NBMA) media like Frame Relay or ATM, where OSPF requires statically configured neighbor addresses. This network type does not elect a DR/BDR because the topology is treated as a collection of point-to-point links. Since Ethernet is broadcast-capable, this is not the default or appropriate network type for a standard Ethernet segment.
When this WOULD be correct
If the exam question asked which OSPF network type supports multiple connections to a central point without requiring a broadcast medium, or if it focused on scenarios involving non-broadcast multi-access (NBMA) networks, then point-to-multipoint nonbroadcast would be the correct answer.
- ✗
Loopback
Why it's wrong here
A loopback interface is a virtual interface that is always up and by default uses the OSPF network type 'loopback' (treated as a stub host). It does not run the broadcast network type, and because it is never connected to another device, no DR/BDR election can occur. Additionally, OSPF advertises loopbacks as /32 host routes even if the netmask is broader.
When this WOULD be correct
If the question were to ask about the OSPF network type that is used for router identification or for creating a stable OSPF endpoint, then Loopback would be the correct answer. For example, a question could specify the importance of using Loopback interfaces for OSPF router IDs.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓BroadcastCorrect answer▾
Why this is correct
On Ethernet segments, OSPF automatically defaults to the broadcast network type. This type relies on multicast hello packets to 224.0.0.5 and elects a Designated Router (DR) and Backup Designated Router (BDR) to minimize the number of adjacencies and reduce LSA flooding on the multi-access link. Therefore, broadcast is the correct network type where DR/BDR election occurs.
✗Point-to-pointWrong answer — click to see why▾
Why this is wrong here
Point-to-point network type is used on serial links or other direct connections where only two routers exist, so no DR/BDR election is needed. On Ethernet, the default OSPF network type is broadcast, not point-to-point.
★ When this WOULD be the correct answer
If the question were to ask about OSPF network types that do not require DR and BDR elections, such as in a scenario involving a direct link between two routers, then 'Point-to-point' would be the correct answer.
Why candidates choose this
Students may confuse point-to-point with Ethernet because both can be used on point-to-point Ethernet links, but the default OSPF network type on Ethernet is broadcast, which triggers DR/BDR election.
✗Point-to-multipoint nonbroadcastWrong answer — click to see why▾
Why this is wrong here
Point-to-multipoint nonbroadcast is a non-default OSPF network type typically used on Frame Relay or other NBMA networks where no broadcast capability exists. Ethernet is a broadcast medium, so this type does not apply by default.
★ When this WOULD be the correct answer
If the exam question asked which OSPF network type supports multiple connections to a central point without requiring a broadcast medium, or if it focused on scenarios involving non-broadcast multi-access (NBMA) networks, then point-to-multipoint nonbroadcast would be the correct answer.
Why candidates choose this
The term 'nonbroadcast' might confuse students into thinking it applies to Ethernet when they consider scenarios without multicast, but Ethernet inherently supports broadcast, making this type incorrect.
✗LoopbackWrong answer — click to see why▾
Why this is wrong here
Loopback interfaces are virtual interfaces used for router identification and testing; they are not physical Ethernet segments. OSPF treats loopbacks as stub networks (host routes) and does not perform DR/BDR election on them.
★ When this WOULD be the correct answer
If the question were to ask about the OSPF network type that is used for router identification or for creating a stable OSPF endpoint, then Loopback would be the correct answer. For example, a question could specify the importance of using Loopback interfaces for OSPF router IDs.
Why candidates choose this
Students might think loopback interfaces participate in OSPF elections because they can be advertised in OSPF, but they are not multi-access and thus do not require DR/BDR.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
Go deeper
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Key term
OSPF network type
OSPF network type defines how the Open Shortest Path First routing protocol operates on a given interface, determining neighbor discovery, adjacency formation, and the election of designated routers.
Key term
OSPF
OSPF is a link-state routing protocol used to find the best path for data packets to travel across IP networks, like a smart GPS that recalculates routes when traffic changes.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-301 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 200-301 exam.