Explanation
BPDU (Bridge Protocol Data Unit) is a message that is exchanged between switches to maintain the spanning tree topology and prevent loops. BPDU protection and BPDU filtering are two features that can be configured on AOS-CX switch ports to enhance security and performance.
BPDU protection is a feature that disables a port if it receives a BPDU, indicating that an unauthorized switch or device has been connected to the port. BPDU protection is typically used on edge ports, which are ports that connect to end devices such as PCs or printers, and are not expected to receive BPDUs. BPDU protection prevents rogue devices from connecting to the network and affecting the spanning tree topology.
BPDU filtering is a feature that prevents a port from sending or receiving BPDUs, effectively isolating the port from the spanning tree topology. BPDU filtering is typically used on inter-switch ports, which are ports that connect to other switches, for specialized use cases such as creating a separate spanning tree domain or reducing the overhead of BPDUs. BPDU filtering should be used with caution, as it can create loops or inconsistencies in the network.
You can find more information about how to configure BPDU protection and BPDU filtering on AOS-CX switch ports in the [Configuring Spanning Tree Protocol - Aruba] page and the [AOS-CX Switching Configuration Guide] page. The other options are not correct because they either use BPDU protection or BPDU filtering on the wrong type of ports or for the wrong purpose. For example, using BPDU protection on inter-switch ports would disable the ports if they receive BPDUs, which are expected in normal operation.
Using BPDU filtering on edge ports would allow rogue devices to connect to the network and create loops or affect the spanning tree topology.