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.

• ✓

  Configure the interface with `switchport mode access`

  Why this is correct

  Configuring 'switchport mode access' forces the interface to operate in permanent access mode, disabling Dynamic Trunking Protocol (DTP) and ensuring the port carries untagged traffic for only one VLAN—usually VLAN 1 by default unless reassigned with 'switchport access vlan'. This deterministic, secure configuration is exactly what an end host expects, because most host NICs send untagged frames and rely on the switch to place them in the proper broadcast domain. It is the industry-standard best practice for connecting PCs, printers, and other typical end devices.

• ✗

  Configure the interface with `switchport mode trunk`

  Why it's wrong here

  A trunk port is designed to carry tagged frames for multiple VLANs simultaneously, typically between switches or to a router that supports 802.1Q tagging. An end host does not usually tag its traffic; if the switchport is set to trunk, the host's untagged frames would be placed in the native VLAN, potentially causing VLAN mismatch, broadcast isolation, and security issues. Therefore trunk mode is not appropriate for a simple end-host connection.

  When this WOULD be correct

  In a scenario where the question specifies that a switch port needs to support multiple VLANs for inter-VLAN routing or to connect to another switch that requires trunking, then `switchport mode trunk` would be the correct configuration.

• ✗

  Configure the interface with `switchport mode dynamic desirable`

  Why it's wrong here

  Dynamic desirable is a Dynamic Trunking Protocol (DTP) mode that actively tries to negotiate a trunk with the connected neighbor. Because an ordinary end host does not generate DTP frames, the port will either remain in access mode after a failed negotiation or, if the host is actually another switch, it could unexpectedly form a trunk, defeating security best practices. This non-deterministic negotiation-based behavior makes it unsuitable for a dedicated end-host port, which should be explicitly forced into access mode.

  When this WOULD be correct

  In a scenario where the question specifies that the switch port should support dynamic trunking negotiation to allow for flexibility in VLAN assignments, `switchport mode dynamic desirable` would be the correct answer. This would apply in environments where multiple VLANs are expected and trunking is acceptable.

• ✗

  Configure the interface with `no switchport`

  Why it's wrong here

  The 'no switchport' command on a multilayer switch converts the interface from a Layer 2 switching port into a routed port that operates at Layer 3, requiring an IP address to forward packets. This eliminates the ability to assign the port to a VLAN and disables normal Ethernet switching, which is not what an end host needs. The port would no longer bridge traffic as a standard access port, and the host would be unable to communicate on the VLAN unless the routed configuration is intentionally desired.

  When this WOULD be correct

  In a scenario where the question specifies that the switch port should be used for routing between different subnets without VLAN tagging, `no switchport` would be the correct configuration to enable Layer 3 routing functionality on that interface.

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?”

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