A network with five switches has been configured to run Rapid Spanning Tree Protocol (RSTP). How many seconds does it take to detect a failure between two neighboring switches?

In a network utilizing Rapid Spanning Tree Protocol (RSTP), the protocol is designed to provide faster convergence times compared to its predecessor, the original Spanning Tree Protocol (STP). One of the key improvements in RSTP is its ability to rapidly detect link failures and reconfigure the topology with minimal disruption.

Under RSTP, when a failure is detected between two neighboring switches, the protocol can react quickly due to its use of a technique known as "Port Role Transition." Specifically, RSTP allows switches to detect a failure within a maximum of 3 seconds. This includes the time taken for the notification of the link failure and subsequent convergence processes to occur.

Thus, the correct answer reflects the efficient and speedy failure detection capability inherent in RSTP, which is designed to enhance network resilience and reduce downtime in the event of a link failure between switches.