easyMultiple Choice
300-410 Practice Question: The default OSPF hello interval on a…
What is the default OSPF hello interval on a point-to-point serial interface?
⚠ Common exam trap
300-410 often tests the default OSPF hello intervals for different network types, and candidates frequently confuse the 10-second interval of point-to-point and broadcast with the 30-second interval of non-broadcast and point-to-multipoint.
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
✓
10 seconds
The default OSPF hello interval on a point-to-point serial interface is 10 seconds. This is because OSPF hello intervals are determined by the network type, and point-to-point networks use a 10-second hello interval. This matches the default for broadcast networks, while non-broadcast and point-to-multipoint networks use 30 seconds.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
10 seconds
Why this is correct
OSPF sets the hello interval to 10 seconds on point-to-point serial interfaces, matching the default for broadcast and point-to-point networks. This satisfies the stem's constraint: the question asks specifically about a point-to-point serial link, not NBMA or non-broadcast, where the interval would instead be 30 seconds.
- ✗
30 seconds
Why it's wrong here
Thirty seconds is the default dead interval on NBMA networks, not a hello interval on point-to-point serial links, so it misidentifies the timer entirely. It is tempting because 30 appears in OSPF NBMA defaults, but point-to-point serial interfaces send hellos every 10 seconds.
- ✗
40 seconds
Why it's wrong here
Forty seconds matches the hello interval used on NBMA and point-to-multipoint networks, not point-to-point serial links, so it would delay neighbour adjacency formation. It is tempting because NBMA media genuinely require 40-second hellos, but a point-to-point serial interface uses the 10-second default.
- ✗
20 seconds
Why it's wrong here
Twenty seconds is the default dead interval, not the hello interval, so it misstates the timer that actually governs neighbour keepalives. It is tempting because the dead interval is four times the hello on broadcast and point-to-point links, making 20 a familiar OSPF value, but on a point-to-point serial interface the hello timer is 10 seconds.
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.
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Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 300-410 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 300-410 exam.