Which command ensures that an interface is statically placed into Access mode?

The command that ensures an interface is statically placed into Access mode is "switchport mode access." This command configures the specific interface to operate in Access mode, where it will only carry traffic for a single VLAN. Unlike Trunk mode, which allows multiple VLANs to traverse the interface, Access mode is primarily used for end devices, like computers or printers, that belong to a single VLAN.

When "switchport mode access" is issued, it explicitly sets the interface to accept frames for the specified access VLAN only, and any frames coming in from other VLANs will not be forwarded. This is crucial in a network environment where segmentation of traffic by VLAN is required for security and management purposes. Additionally, once an interface is set to Access mode, it becomes easier to manage and monitor traffic since it will only communicate with devices on that designated VLAN.

The other commands do not function to place an interface into Access mode. "switchport access vlan" is used to define which VLAN the access port belongs to after it has been set to Access mode, while "switchport mode trunk" switches the interface to Trunk mode, allowing multiple VLANs. "interface mode access" is not a valid command in Cisco IOS. Overall, using "