mediummultiple choiceObjective-mapped

An organization uses OSPF as its interior gateway protocol in a multi-area design. After a core router failure, the network takes several seconds to reconverge. Which technology can be implemented to improve convergence speed?

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An organization uses OSPF as its interior gateway protocol in a multi-area design. After a core router failure, the network takes several seconds to reconverge. Which technology can be implemented to improve convergence speed?

Answer choices

Why each option matters

Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.

A

Distractor review

Implement LSA throttling

LSA throttling controls the rate at which LSAs are generated, which can prevent network flooding but does not speed up failure detection.

B

Distractor review

Enable OSPF fast hello timers

Fast hello timers reduce the hello interval, which can speed up neighbor loss detection, but BFD is usually faster and more consistent.

C

Best answer

Configure BFD (Bidirectional Forwarding Detection)

BFD provides sub-second failure detection, allowing OSPF to converge much faster than with default timers.

D

Distractor review

Convert all areas to stub areas

Stub areas reduce the types of LSAs but do not directly improve convergence speed after a failure.

Common exam trap

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.

Technical deep dive

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.

Related practice questions

Related N10-009 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

More questions from this exam

Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.

Question 1

A network engineer needs to connect two switches located 400 meters apart. The cable run includes high electromagnetic interference from nearby machinery. The engineer decides to use fiber optic cabling. Which transceiver type and fiber combination should be used to ensure the link reaches 400 meters while remaining cost-effective?

Question 2

A network engineer is designing a new switched network and needs to ensure that broadcast traffic from one department does not reach another department's workstations. The engineer plans to use VLANs. Which of the following must be configured on the switches to isolate broadcast domains as intended?

Question 3

A security engineer is configuring a site-to-site VPN between two branch offices. The requirement is to encrypt all traffic between the two networks using IPsec. Which IPsec mode should be used to encrypt the entire IP packet including the original header?

Question 4

A network administrator is connecting two switches to increase bandwidth and provide redundancy. Which technology should be used to combine multiple physical links into a single logical link?

Question 5

A network administrator is experiencing issues where unauthorized devices are offering IP addresses to clients, causing connectivity problems. Which security feature should be enabled on switches to prevent this?

Question 6

A network administrator is troubleshooting a connectivity issue and suspects the problem is related to the physical cabling. At which layer of the OSI model should the administrator begin their investigation?

FAQ

Questions learners often ask

What does this N10-009 question test?

OSPF neighbours must agree on key parameters.

What is the correct answer to this question?

The correct answer is: Configure BFD (Bidirectional Forwarding Detection) — Bidirectional Forwarding Detection (BFD) provides rapid failure detection independent of the routing protocol. When a link fails, BFD can detect it in milliseconds and trigger OSPF to converge much faster than relying on OSPF's own hello timer (typically 10 seconds). LSA throttling (option A) prevents floods but does not speed detection. OSPF fast hello (option B) can reduce hello intervals but may not be as fast as BFD. OSPF stub areas (option D) reduce LSA types but do not directly affect convergence time after a failure.

What should I do if I get this N10-009 question wrong?

Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.

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