Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
Which command places a switch interface into trunking mode directly instead of relying on negotiation?
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
switchport mode trunk
This is correct because it directly forces the interface into trunk mode.
B
Distractor review
switchport access vlan 10
This is wrong because it assigns an access VLAN and does not place the interface into trunking mode.
C
Distractor review
switchport mode dynamic auto
This is wrong because dynamic auto relies on negotiation and does not directly force trunking.
D
Distractor review
spanning-tree portfast
This is wrong because PortFast is an STP feature for edge ports, not a trunk-mode command.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is selecting the dynamic trunking commands like `switchport mode dynamic auto` as the correct way to enable trunking. These modes depend on Dynamic Trunking Protocol negotiation and do not guarantee the interface will become a trunk port. If the neighboring device does not actively negotiate trunking, the port may remain in access mode, causing VLAN traffic to be dropped or misrouted. This subtlety often confuses candidates who overlook the difference between forced trunk mode and negotiation-based trunking.
Technical deep dive
How to think about this question
In Cisco switching, trunk ports carry traffic for multiple VLANs between switches or other network devices. The command `switchport mode trunk` explicitly configures an interface to operate as a trunk port, bypassing any negotiation protocols like Dynamic Trunking Protocol (DTP). This direct configuration ensures the interface immediately tags frames with VLAN identifiers and forwards traffic for all allowed VLANs, which is essential for VLAN segmentation and inter-switch communication. Cisco switches support several trunking modes, including dynamic auto, dynamic desirable, trunk, and access. The `switchport mode trunk` command forces the interface into trunk mode without waiting for negotiation, making the administrative intent explicit and preventing ambiguity. In contrast, dynamic auto mode places the port in a passive state, waiting for the other side to initiate trunking, which can lead to inconsistent or unexpected trunk formation. A common exam trap is confusing dynamic trunking modes with forced trunk mode. Candidates often mistake `switchport mode dynamic auto` as enabling trunking directly, but it actually relies on negotiation and may result in an access port if the other side does not initiate trunking. Understanding this distinction is critical for both exam success and real-world network stability, as forced trunking avoids negotiation failures and ensures consistent VLAN tagging across links.
KKey Concepts to Remember
- The `switchport mode trunk` command directly forces a switch interface to operate as a trunk port, carrying multiple VLANs without negotiation.
- Dynamic trunking modes like `dynamic auto` rely on DTP negotiation and may not activate trunking if the neighbor does not initiate it.
- Trunk ports tag Ethernet frames with VLAN identifiers to segregate traffic across a shared physical link between switches.
- Access ports carry traffic for a single VLAN and do not tag frames, making `switchport access vlan` incompatible with trunking.
- Spanning Tree Protocol features like PortFast do not influence trunking behavior and serve different purposes related to loop prevention.
- Explicitly configuring trunk mode avoids negotiation failures and ensures consistent VLAN traffic forwarding in Cisco networks.
- Dynamic Trunking Protocol (DTP) automates trunk negotiation but can introduce ambiguity and is often disabled in secure environments.
- Understanding the difference between forced trunk mode and negotiation-based trunking is critical for CCNA exam success and network reliability.
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?
The `switchport mode trunk` command directly forces a switch interface to operate as a trunk port, carrying multiple VLANs without negotiation.
What is the correct answer to this question?
The correct answer is: switchport mode trunk — The direct command is `switchport mode trunk`. In plain language, this tells the switch to behave as a trunk port rather than waiting to negotiate that role through DTP. That makes the administrative intent clear and avoids ambiguity. In many production environments, explicit configuration is preferred because it is easier to understand and troubleshoot than relying on negotiation behavior. This is a core CCNA switching idea because trunks and access ports serve very different purposes. The wrong answers either describe negotiation states or commands that relate to other aspects of VLAN behavior. The best answer is the one that directly forces the interface into trunk mode instead of merely suggesting or passively waiting for trunking.
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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