Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A switch interface is configured as `dynamic desirable`, and the peer interface is configured as `dynamic auto`. What is the most likely result?
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
Best answer
The link is likely to become a trunk.
This is correct because dynamic desirable can initiate trunk negotiation with a dynamic auto peer.
B
Distractor review
The link becomes a routed port.
This is wrong because DTP negotiation does not convert a port into a Layer 3 routed interface.
C
Distractor review
All VLANs are deleted from both switches.
This is wrong because DTP does not delete VLANs.
D
Distractor review
The port is immediately error-disabled.
This is wrong because this DTP pairing does not normally cause err-disable behavior.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A common exam trap is assuming that two switch ports both set to dynamic auto will form a trunk link. Since dynamic auto is a passive mode, neither side initiates trunk negotiation, so the link remains an access port. This misconception leads candidates to incorrectly select auto/auto as a trunking pair. The exam tests your understanding that at least one side must be dynamic desirable or trunk mode to actively negotiate trunking. Misreading the roles of dynamic auto and dynamic desirable can cause you to choose incorrect answers about trunk formation behavior.
Technical deep dive
How to think about this question
Dynamic Trunking Protocol (DTP) is a Cisco proprietary protocol used to automate the negotiation of trunk links between switches. It simplifies VLAN traffic management by dynamically establishing trunk links without manual configuration. DTP operates with different modes: dynamic desirable actively attempts to convert the link into a trunk, dynamic auto passively waits for the other side to initiate trunking, trunk mode forces trunking, and access mode disables trunking. Understanding these modes is crucial for configuring VLAN trunks correctly in Cisco networks. When one switch port is set to dynamic desirable and the other to dynamic auto, the dynamic desirable port initiates the trunk negotiation, and the dynamic auto port responds, resulting in a successful trunk link. This behavior contrasts with the auto/auto combination, where neither side initiates trunking, causing the link to remain an access port. The dynamic desirable mode actively sends DTP frames to negotiate trunking, while dynamic auto listens and replies, enabling trunk formation when paired correctly. A common exam trap is confusing the dynamic auto mode as actively negotiating trunking, leading to the mistaken belief that auto/auto will form a trunk. In reality, both sides must not be passive for trunking to form automatically. Practically, this means network engineers must configure at least one side as dynamic desirable or trunk to ensure trunk establishment. This knowledge helps avoid misconfigurations that can cause VLAN traffic segmentation issues and connectivity problems in Cisco switched networks.
KKey Concepts to Remember
- Dynamic Trunking Protocol (DTP) automates trunk negotiation between Cisco switch ports to simplify VLAN traffic management.
- A switch port configured as dynamic desirable actively initiates trunk negotiation by sending DTP frames to the peer.
- A switch port configured as dynamic auto passively waits and responds to DTP negotiation requests but does not initiate them.
- When one port is dynamic desirable and the other is dynamic auto, the link successfully negotiates and becomes a trunk.
- If both ports are set to dynamic auto, neither initiates trunk negotiation, so the link remains an access port.
- DTP negotiation does not convert a switch port into a Layer 3 routed port; it only manages Layer 2 trunking.
- Incorrect DTP mode pairings can cause VLAN traffic segmentation and connectivity issues in switched networks.
- Understanding DTP modes prevents misconfiguration and ensures proper VLAN trunk formation in Cisco environments.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
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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 router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
Dynamic Trunking Protocol (DTP) automates trunk negotiation between Cisco switch ports to simplify VLAN traffic management.
What is the correct answer to this question?
The correct answer is: The link is likely to become a trunk. — The most likely result is that the link becomes a trunk. In simple terms, `dynamic desirable` actively tries to negotiate a trunk, while `dynamic auto` listens and responds. Because one side is willing to initiate the process, trunking can be established if the rest of the configuration is compatible. This question tests whether you know the difference between passive and active DTP behavior. The classic failure pairing is auto/auto. Desirable/auto, by contrast, is a normal path to trunk formation.
What should I do if I get this 200-301 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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