- A
Both BFD sessions will use the same timer values because OSPF is configured with 'bfd all-interfaces'.
Why wrong: BFD timers are interface-specific; 'bfd all-interfaces' only enables BFD on all OSPF interfaces, but each interface retains its own timers.
- B
The BFD session on GigabitEthernet0/0 will detect failures in 300 ms, and on GigabitEthernet0/1 in 600 ms.
Correct. Detection time = multiplier * interval. For Gi0/0: 3*100=300 ms; for Gi0/1: 3*200=600 ms.
- C
The BFD session on GigabitEthernet0/1 will not form because the interval is too high.
Why wrong: 200 ms is a valid BFD interval; there is no upper limit that prevents session formation.
- D
The router will use the minimum interval across all interfaces for consistency.
Why wrong: BFD timers are independent per interface.
Quick Answer
The answer is that the BFD session on GigabitEthernet0/0 will detect failures in 300 ms, and on GigabitEthernet0/1 in 600 ms. This is correct because BFD per-interface timer configuration allows each interface to independently define its own transmit interval, receive interval, and multiplier, and the failure detection time is calculated as the configured interval multiplied by the multiplier. In this scenario, the bfd interval command sets both the desired transmit and minimum receive intervals to the same value, so GigabitEthernet0/0 uses 100 ms times a multiplier of 3 for 300 ms, while GigabitEthernet0/1 uses 200 ms times 3 for 600 ms. On the Cisco CCNP ENARSI 300-410 exam, this question tests your understanding that BFD timers are interface-specific, not global, even when OSPF is enabled with bfd all-interfaces; a common trap is assuming the multiplier applies to the OSPF hello timer rather than the BFD session itself. Remember the memory tip: “BFD multiplies its own interval, not the routing protocol’s.”
300-410 Bidirectional Forwarding Detection (BFD) Practice Question
This 300-410 practice question tests your understanding of bidirectional forwarding detection (bfd). This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Examine the partial BFD configuration on a router:
interface GigabitEthernet0/0
bfd interval 100 min_rx 100 multiplier 3 !
interface GigabitEthernet0/1
bfd interval 200 min_rx 200 multiplier 3 !
router ospf 1
bfd all-interfaces !
The router has OSPF neighbors on both interfaces. Which statement is true?
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
The BFD session on GigabitEthernet0/0 will detect failures in 300 ms, and on GigabitEthernet0/1 in 600 ms.
BFD timers are configured per interface. Each BFD session independently uses the timers configured on its respective interface. The multiplier is applied per session.
Key principle: OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Both BFD sessions will use the same timer values because OSPF is configured with 'bfd all-interfaces'.
Why it's wrong here
BFD timers are interface-specific; 'bfd all-interfaces' only enables BFD on all OSPF interfaces, but each interface retains its own timers.
- ✓
The BFD session on GigabitEthernet0/0 will detect failures in 300 ms, and on GigabitEthernet0/1 in 600 ms.
Why this is correct
Correct. Detection time = multiplier * interval. For Gi0/0: 3*100=300 ms; for Gi0/1: 3*200=600 ms.
Related concept
OSPF neighbours must agree on key parameters.
- ✗
The BFD session on GigabitEthernet0/1 will not form because the interval is too high.
Why it's wrong here
200 ms is a valid BFD interval; there is no upper limit that prevents session formation.
- ✗
The router will use the minimum interval across all interfaces for consistency.
Why it's wrong here
BFD timers are independent per interface.
Common exam traps
Common exam trap: OSPF can fail even when IP connectivity looks correct
OSPF neighbour formation depends on matching areas, timers, network type, authentication and passive-interface behaviour. Do not choose an answer only because the devices can ping.
Detailed technical explanation
How to think about this question
OSPF questions usually test the details that control adjacency and route selection. Read the neighbour state, area, router ID and interface configuration before deciding what is wrong.
KKey Concepts to Remember
- OSPF neighbours must agree on key parameters.
- Router ID selection can affect neighbour relationships and LSDB output.
- OSPF cost influences the preferred path.
- A route can appear in OSPF information but not become the installed route.
TExam Day Tips
- Check area mismatch first when OSPF adjacency fails.
- Review passive interfaces when a network is advertised but no neighbour forms.
- Use show ip ospf neighbor and show ip route clues carefully.
Key takeaway
OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
Real-world example
How this comes up in practice
A network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.
What to study next
Got this wrong? Here's your next step.
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related 300-410 OSPF questions on adjacency and route selection.
- →
Bidirectional Forwarding Detection (BFD) — study guide chapter
Learn the concepts, then practise the questions
- →
Bidirectional Forwarding Detection (BFD) practice questions
Targeted practice on this topic area only
- →
All 300-410 questions
2,152 questions across all exam domains
- →
Cisco CCNP ENARSI 300-410 study guide
Full concept coverage aligned to exam objectives
- →
300-410 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 300-410 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Layer 3 Technologies practice questions
Practise 300-410 questions linked to Layer 3 Technologies.
EIGRP Troubleshooting practice questions
Practise 300-410 questions linked to EIGRP Troubleshooting.
OSPF Troubleshooting (v2/v3) practice questions
Practise 300-410 questions linked to OSPF Troubleshooting (v2/v3).
BGP Troubleshooting practice questions
Practise 300-410 questions linked to BGP Troubleshooting.
Route Redistribution practice questions
Practise 300-410 questions linked to Route Redistribution.
Policy-Based Routing (PBR) practice questions
Practise 300-410 questions linked to Policy-Based Routing (PBR).
VRF-Lite practice questions
Practise 300-410 questions linked to VRF-Lite.
Route Maps and Route Filtering practice questions
Practise 300-410 questions linked to Route Maps and Route Filtering.
Administrative Distance practice questions
Practise 300-410 questions linked to Administrative Distance.
Route Summarization practice questions
Practise 300-410 questions linked to Route Summarization.
Bidirectional Forwarding Detection (BFD) practice questions
Practise 300-410 questions linked to Bidirectional Forwarding Detection (BFD).
VPN Technologies practice questions
Practise 300-410 questions linked to VPN Technologies.
Practice this exam
Start a free 300-410 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 300-410 question test?
Bidirectional Forwarding Detection (BFD) — This question tests Bidirectional Forwarding Detection (BFD) — OSPF neighbours must agree on key parameters..
What is the correct answer to this question?
The correct answer is: The BFD session on GigabitEthernet0/0 will detect failures in 300 ms, and on GigabitEthernet0/1 in 600 ms. — BFD timers are configured per interface. Each BFD session independently uses the timers configured on its respective interface. The multiplier is applied per session.
What should I do if I get this 300-410 question wrong?
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related 300-410 OSPF questions on adjacency and route selection.
What is the key concept behind this question?
OSPF neighbours must agree on key parameters.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 18, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.