Which command is used to enable BPDU Guard on a switch port?

The command used to enable BPDU Guard on a switch port is "spanning-tree bpduguard enable." This command is specifically designed to configure BPDU Guard at the interface level. When enabled on a port that is configured with PortFast, BPDU Guard prevents that port from receiving Bridge Protocol Data Units (BPDUs). If any BPDU is received on the port, it will immediately go into an error-disabled state, effectively protecting the network from potential loops and misconfigurations.

Other commands related to spanning-tree, such as enabling PortFast, are important for optimizing the switch's operation, but they do not specifically enable BPDU Guard. Therefore, while these commands serve different functions in the spanning-tree configuration, only "spanning-tree bpduguard enable" directly addresses the enabling of BPDU Guard functionality.