CCNA Switching and Network Access Practice Question
A switchport connected to another switch is configured as an access port by mistake. Which symptom is most likely in a multi-VLAN design?
⚠ Common exam trap
Be cautious not to confuse physical link status with logical configuration issues. An access port will not drop the link but will restrict traffic to a single VLAN.
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
✓
Only one VLAN is likely to pass correctly, while other VLAN traffic across the link fails
The most likely symptom is that only one VLAN’s traffic works correctly across the link while traffic for other VLANs fails. In plain language, an access port belongs to one VLAN in normal switching behavior. If an inter-switch link that should carry multiple VLANs is accidentally configured as an access port, the network loses the ability to transport the other VLANs. The physical link may stay up, which can make the problem seem subtle, but the logical role of the port is wrong.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Only one VLAN is likely to pass correctly, while other VLAN traffic across the link fails
Why this is correct
An access port is configured to carry exactly one untagged VLAN, known as the access VLAN. When connected to another switch, that link will only pass traffic belonging to the access VLAN; frames from other VLANs that arrive expecting trunk tagging will be dropped or misclassified. This causes a failure for all other VLANs across that link, because the access port does not support 802.1Q trunking or multi-VLAN tagging.
- ✗
The link negotiates as a trunk but drops all VLAN traffic
Why it's wrong here
A switchport in access mode does not participate in trunk negotiation; DTP is disabled and the link will not become a trunk. Even if the neighboring switch tries to send tagged frames, an access port will strip or ignore tags, but it will still forward untagged frames in the access VLAN. Therefore, the link does not negotiate as a trunk, and it does not drop all VLAN traffic—it continues to carry the access VLAN (and possibly the native VLAN if trunking were misconfigured).
When this WOULD be correct
In a scenario where a question asks about a switchport configured as a trunk port but experiencing issues, option B could be correct if the switch is misconfigured and the link is intended to route traffic for multiple VLANs. The question would need to imply that the port should have been a routed port but was incorrectly set up.
- ✗
The switch generates excessive broadcasts on all VLANs
Why it's wrong here
An access port misconfiguration only affects VLAN tagging and membership; it does not alter broadcast generation or routing metrics. Broadcasts within the configured access VLAN are still forwarded normally, but the switch does not generate excessive broadcasts on all VLANs. The OSPF metric, a cost value used for route selection, is completely unrelated to Layer 2 switchport access mode. Thus, this symptom is not a plausible result of the described misconfiguration.
When this WOULD be correct
In a question about OSPF behavior during a network topology change, such as adding or removing interfaces, where the reset of OSPF metrics is a direct consequence of those changes, this option would be correct.
- ✗
The switch stops learning MAC addresses entirely
Why it's wrong here
MAC address learning occurs on a per-port basis independent of the port mode, so an access port continues to learn MAC addresses from frames it receives in its access VLAN. The switch records those source MAC addresses in its CAM table for that VLAN; the problem is not a failure to learn, but rather that the port only handles one VLAN's traffic. Therefore, the switch does not stop learning MAC addresses entirely; it simply restricts learning to the access VLAN.
When this WOULD be correct
In a scenario where a switch is misconfigured to not allow any VLAN traffic due to a faulty configuration or hardware failure, a question could ask what happens to MAC address learning. In that case, if the switch is unable to process any traffic, it might stop learning MAC addresses altogether.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓Only one VLAN is likely to pass correctly, while other VLAN traffic across the link failsCorrect answer▾
Why this is correct
An access port is configured to carry exactly one untagged VLAN, known as the access VLAN. When connected to another switch, that link will only pass traffic belonging to the access VLAN; frames from other VLANs that arrive expecting trunk tagging will be dropped or misclassified. This causes a failure for all other VLANs across that link, because the access port does not support 802.1Q trunking or multi-VLAN tagging.
✗The link negotiates as a trunk but drops all VLAN trafficWrong answer — click to see why▾
Why this is wrong here
An access port cannot negotiate trunking; it will never become a trunk, so it does not drop all VLAN traffic—it simply forwards only one VLAN's traffic.
★ When this WOULD be the correct answer
In a scenario where a question asks about a switchport configured as a trunk port but experiencing issues, option B could be correct if the switch is misconfigured and the link is intended to route traffic for multiple VLANs. The question would need to imply that the port should have been a routed port but was incorrectly set up.
Why candidates choose this
Candidates may find this option tempting because they might confuse access ports with routed ports, believing that misconfigurations could lead to automatic adjustments in port types, especially in complex multi-VLAN environments.
✗The switch generates excessive broadcasts on all VLANsWrong answer — click to see why▾
Why this is wrong here
An access port does not generate excessive broadcasts; broadcast storms are unrelated to an access/trunk misconfiguration.
★ When this WOULD be the correct answer
In a question about OSPF behavior during a network topology change, such as adding or removing interfaces, where the reset of OSPF metrics is a direct consequence of those changes, this option would be correct.
Why candidates choose this
Candidates may choose this option due to a misunderstanding of how Layer 2 configurations impact Layer 3 protocols, mistakenly believing that access port misconfigurations would affect OSPF metrics.
✗The switch stops learning MAC addresses entirelyWrong answer — click to see why▾
Why this is wrong here
This option is wrong because an access port will still learn MAC addresses for devices within the configured VLAN, but it will not learn MAC addresses for devices in other VLANs. Thus, the switch does not stop learning MAC addresses entirely.
★ When this WOULD be the correct answer
In a scenario where a switch is misconfigured to not allow any VLAN traffic due to a faulty configuration or hardware failure, a question could ask what happens to MAC address learning. In that case, if the switch is unable to process any traffic, it might stop learning MAC addresses altogether.
Why candidates choose this
Candidates might choose this option because they associate access ports with VLAN limitations and mistakenly believe that this would lead to a complete halt in MAC address learning, overlooking the fact that learning is still possible within the configured VLAN.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
Go deeper
Related to this question
Learn chapter
Configuring Switch Ports for Desktops, VoIP Phones, APs, IoT, and Virtualized Hosts
Key term
Switch
A switch is a networking device that connects devices on a local area network and uses MAC addresses to forward data only to the intended recipient.
Key term
Access port
An access port is a switch port that connects to a single end device, like a computer or printer, and carries traffic for only one VLAN.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-301 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 200-301 exam.