Cisco CCNA 200-301 Practice Question

Configuring Root Guard on the interfaces prevents downstream switches from influencing the spanning-tree topology by blocking superior BPDUs received on those ports. This ensures the distribution switch maintains control over the spanning-tree calculations, preserving the intended network hierarchy. Enabling BPDU Guard would place a port in error-disabled state upon receiving any BPDU, which is suitable for ports connected to end devices, not other switches. Enabling PortFast is meant for ports connected to end devices to speed up their transition to the forwarding state, and does not prevent switches from affecting the spanning-tree topology. Disabling Spanning Tree Protocol is not advisable as it can lead to broadcast storms and network loops.