How do you configure the native VLAN on a trunk port?

The correct way to configure the native VLAN on a trunk port is through the command that specifies the trunking context, which is the second option. In this case, the command "switchport trunk native vlan vlan-number" directly establishes the native VLAN on a trunk interface.

When you configure a VLAN on a trunk port, it is essential to indicate that the settings pertain to the trunking protocol because trunk ports carry multiple VLANs. The use of the term "trunk" in the command clarifies the port's role and ensures that the switch understands that you are specifying a parameter relevant to trunking.

The native VLAN is critical for legacy equipment and for interoperability with devices that may not understand VLAN tagging. By explicitly setting the native VLAN in the trunking context, you ensure that untagged traffic sent through the trunk is properly recognized and associated with the specified VLAN. This command effectively instructs the switch to treat any packets received without a VLAN tag on that trunk port as belonging to the specified native VLAN.

Other options do not provide the correct syntax or context needed to assign the native VLAN correctly, which is why they are not suitable for configuring the native VLAN on trunk ports.