Which of the following configurations ensures redundancy in network topologies?

Redundancy in network topologies is essential for ensuring high availability and reliability of network services. Each of the listed configurations plays a role in providing this redundancy.

Link aggregation protocols allow multiple network connections to combine their bandwidth and create a single logical connection. This not only increases the overall bandwidth but also provides redundancy. If one of the links in the aggregation fails, traffic can still flow through the remaining links, maintaining connectivity.

Spanning Tree Protocol (STP) is designed to prevent loops in network topologies by selectively blocking certain paths. When a primary link experiences a failure, STP can re-enable a previously blocked path, effectively providing backup routes and ensuring redundancy in the network.

Rapid Spanning Tree Protocol (RSTP) is an evolution of STP that provides faster convergence when links change state, allowing for quicker failover. It enhances the redundancy capabilities by enabling faster recovery from link failures, thus ensuring that there is minimal disruption in the network.

All of these configurations contribute to creating a resilient network environment where redundancy is built into the topology, ensuring that services remain available even in the event of various failures. This makes the inclusion of all these options necessary for achieving optimal redundancy in network designs.