CCNA Switching and Network Access Practice Question

Answer analysis

Option-by-option breakdown

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

• ✓

  The two ends disagree on whether the link is a trunk or an access port.

  Why this is correct

  A switchport in trunk mode encapsulates frames with 802.1Q tags and expects to receive tagged frames, while an access port transmits and receives only untagged frames in a single VLAN. When one end is a trunk and the other is an access port, the access port will drop tagged frames or treat them as invalid, and the trunk port may not accept the untagged frames sent by the access side. This role mismatch prevents proper VLAN segmentation and causes the link to fail at Layer 2.

• ✗

  The switches must both use the same hostname.

  Why it's wrong here

  Hostnames are purely cosmetic identifiers used for device management and CLI prompts; they have no influence on the Data Link layer behavior of a switchport. The operational mode (access or trunk) is determined by the switchport mode configuration and DTP negotiation, not by the name assigned to the switch. Therefore, requiring identical hostnames would neither cause nor fix an inconsistency between the two ends of the link.

  When this WOULD be correct

  In a different scenario where a question asks about the importance of hostname consistency for management or monitoring purposes in a network, option B could be correct. For example, if the exam question focused on network management tools that rely on hostname resolution, having the same hostname could be crucial.

• ✗

  The native VLAN must be set to 1 on both sides first.

  Why it's wrong here

  Setting the native VLAN to 1 on both sides would only ensure that untagged frames on a trunk are placed in the same VLAN, but it does not address the fact that one side expects 802.1Q-tagged frames while the other expects untagged frames. The native VLAN mismatch is a possible secondary fault, but the primary issue here is the trunk/access role disagreement. Unless both interfaces are configured as trunk, the native VLAN setting alone cannot make the link function correctly.

  When this WOULD be correct

  In a different question, if the scenario involved two switches configured as trunks but with different native VLANs, then specifying that the native VLAN must be set to 1 on both sides could be correct. This would be relevant if the question focused on ensuring consistent native VLAN settings for proper communication.

• ✗

  The ports need OSPF enabled.

  Why it's wrong here

  OSPF is a Link State routing protocol that operates at Layer 3 and requires IP addresses and routing tables to exchange routes; it has absolutely no role in determining whether a switchport is an access or trunk port. Even if OSPF were enabled on both switches, it would not alter the switchport mode or the encapsulation of Ethernet frames on the link. The problem is strictly a Layer 2 configuration mismatch and can only be resolved by aligning the switchport modes.

  When this WOULD be correct

  In a different scenario where the question asks about routing protocols and their necessity for inter-VLAN communication, option D could be correct if the exam context involves enabling OSPF on interfaces to facilitate routing between VLANs across different switches.

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.

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?”

Go deeper

Related to this question