Courseiva
MPLS and Segment RoutingeasyMultiple ChoiceObjective-mapped

350-501 OSPF LSA Flooding Practice Question

A service provider has deployed segment routing with OSPF as the IGP in its core network. The network consists of 100 routers in a single area. The operations team reports that after a link failure between Router X and Router Y, traffic from Router A to Router B is taking a suboptimal path even though IGP convergence is complete and all routers have updated their LSDB. Router A and Router B are both segment routing capable. The team verifies that no SR-TE policies are configured and that all routers are using the default SPF algorithm. The expected shortest path from A to B should go through the newly restored link, but instead it still traverses an alternate path. Which action should resolve the issue?

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

Execute 'clear ip ospf process' on all routers along the expected path.

The suboptimal path persists despite LSDB convergence due to OSPF not performing a full SPF recalculation after the link restoration. 'clear ip ospf process' forces a complete SPF computation and reflooding of LSAs, which corrects the routing table. Option A is incorrect because adjacency SIDs are dynamically allocated and removing/re-adding them does not address the root cause. Option C is incorrect because SR-TE policies are not required for shortest-path forwarding and may unnecessarily override the IGP. Option D is incorrect because clearing MPLS forwarding labels does not affect the IGP routing decision; the issue is at Layer 3, not label allocation.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Remove and re-add the adjacency SID configuration on the restored link.

    Why it's wrong here

    Removing and re-adding adjacency SID configuration is unnecessary; adjacency SIDs are automatically allocated and not the root cause of the suboptimal path.

  • Execute 'clear ip ospf process' on all routers along the expected path.

    Why this is correct

    Correct. 'clear ip ospf process' forces a fresh LSA flood and SPF computation, updating the routing table to use the restored link.

  • Configure an SR-TE policy from A to B with an explicit path using the restored link.

    Why it's wrong here

    Configuring an SR-TE policy is an alternative but not the most direct resolution; the issue is with IGP SPF behavior, not lack of TE policies.

  • Issue 'clear mpls forwarding labels' on Router A to rebuild the label table.

    Why it's wrong here

    Clearing MPLS forwarding labels does not affect OSPF's SPF calculation; the routing table remains unchanged until SPF is recomputed.

Visual reference

R1 R2 R3 R4 10 100 10 100 OSPF picks R1→R2→R4 (cost 20) over R1→R3→R4 (cost 200)

About these practice questions

This 350-501 question is part of Courseiva's 971-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

JA

Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

This 350-501 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 350-501 exam.