Cisco Certified Network Associate (CCNA) Practice Exam

How is a VLAN configured on an interface?

1. By using the command switchport allow vlan

2. By using the command switchport access vlan

3. By assigning IP address to the VLAN

4. By renaming the VLAN in the switch

The correct answer is: By using the command switchport access vlan

To configure a VLAN on an interface, the command used is "switchport access vlan" followed by the VLAN ID. This command assigns the specific VLAN to the access port on the switch, ensuring that all traffic coming through this port is tagged with the specified VLAN's ID. This is a critical step in segmenting network traffic and enhancing security and performance within a network. When an access port is configured for a VLAN, it becomes a member of that VLAN, allowing devices connected to the port to communicate with each other as if they were on the same physical network while remaining isolated from devices in other VLANs. The command "switchport allow vlan" is not used for configuring VLAN membership on an interface; instead, it is typically used in trunk port configuration to specify which VLANs are allowed on that trunk. Assigning an IP address to the VLAN is part of the VLAN interface configuration rather than interface assignment, and renaming a VLAN does not affect its configuration on individual switch ports. Thus, using "switchport access vlan" is the correct approach for associating a specific interface with a VLAN in a Cisco networking environment.