Question 407 of 2,015
VLANs and TrunkingmediumDrag & DropObjective-mapped

Quick Answer

The correct order for DTP negotiation steps ends with the trunk forwarding traffic for multiple VLANs. This sequence begins with the interface defaulting to either dynamic desirable or dynamic auto mode; when one side is set to trunk, it actively sends DTP frames to negotiate the link. The neighboring switch responds only if its port is in a compatible mode—such as trunk, desirable, or auto—and once both agree, the link transitions to trunking, allowing the final step where both ends forward traffic for multiple VLANs. On the ENCOR 350-401 exam, this drag-and-drop task tests your understanding of how Cisco’s proprietary Dynamic Trunking Protocol operates at Layer 2, often tripping candidates who forget that dynamic auto will never initiate negotiation, only respond. A common trap is assuming both sides must be set to trunk; in reality, trunk plus desirable or auto works. Remember the mnemonic “DAD TALKS” for the order: Default mode, Advertise, Decide, Trunk, All VLANs forward.

350-401 VLANs and Trunking Practice Question

This 350-401 practice question tests your understanding of vlans and trunking. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.

Drag and drop the steps of Dynamic Trunking Protocol (DTP) negotiation into the correct order, from first to last.

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "first"

    Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.

Question 1mediumdrag order
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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

Set interface to switchport mode trunk

DTP negotiation begins with the interface defaulting to dynamic desirable or auto mode. If a switchport is set to trunk, DTP sends frames to negotiate. The neighbor responds if in a compatible mode. Once agreed, the link becomes trunking. Finally, both ends forward traffic for multiple VLANs.

Key principle: OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.

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 350-401 OSPF questions on adjacency and route selection.

Related practice questions

Related 350-401 practice-question pages

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FAQ

Questions learners often ask

What does this 350-401 question test?

VLANs and Trunking — This question tests VLANs and Trunking — OSPF neighbours must agree on key parameters..

What is the correct answer to this question?

The correct answer is: Set interface to switchport mode trunk — DTP negotiation begins with the interface defaulting to dynamic desirable or auto mode. If a switchport is set to trunk, DTP sends frames to negotiate. The neighbor responds if in a compatible mode. Once agreed, the link becomes trunking. Finally, both ends forward traffic for multiple VLANs.

What should I do if I get this 350-401 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 350-401 OSPF questions on adjacency and route selection.

Are there clue words in this question I should notice?

Yes — watch for: "first". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.

What is the key concept behind this question?

OSPF neighbours must agree on key parameters.

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Last reviewed: Jun 18, 2026

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This 350-401 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 350-401 exam.