Rapid Spanning Tree Protocol (RSTP)

B

Enhancements enable RSTP to achieve sub-second forwarding and network convergence. RSTP is backward-compatible with legacy STP. If legacy STP BPDU is detected on a link, then an RSTP-capable bridge will revert to legacy STP on that given port.

Rapid Spanning Tree Protocol (RSTP) is an enhancement to the original Spanning Tree Protocol (STP) which provides faster convergence and better use of available bandwidth in the network.

Regarding the given options, we can evaluate them as follows:

A. If a device configured for RSTP receives STP BPDUs, it sends STP BPDUs. This statement is incorrect. If a device is configured for RSTP, it will send RSTP BPDUs, not STP BPDUs. The device will not revert to the slower STP protocol.

B. If a device configured for RSTP receives STP BPDUs, it forwards them as STP BPDUs. This statement is also incorrect. RSTP is backward compatible with STP, but it does not forward STP BPDUs. If an RSTP device receives an STP BPDU, it will interpret it as an RSTP BPDU and proceed accordingly.

C. If a device configured for RSTP receives STP BPDUs, it continues to send RSTP BPDUs. This statement is correct. RSTP is backward compatible with STP, so if an RSTP device receives an STP BPDU, it will continue to send RSTP BPDUs. This behavior helps to ensure that the RSTP device does not revert to STP and maintains the faster convergence times and better use of available bandwidth that RSTP provides.

D. If a device configured for RSTP receives STP BPDUs, it sends RSTP and STP BPDUs. This statement is incorrect. An RSTP device will not send both RSTP and STP BPDUs simultaneously. If an RSTP device receives an STP BPDU, it will continue to send RSTP BPDUs, as stated in option C.

In summary, the correct statement about RSTP is that if a device configured for RSTP receives STP BPDUs, it continues to send RSTP BPDUs.