What does link aggregation allow between switches in a broadcast domain?

Link aggregation allows for the combination of multiple network connections in parallel to increase throughput and provide redundancy. In the context of switches within a broadcast domain, it specifically enables the use of multiple redundancy links between switches while preventing the formation of Layer 2 forwarding loops.

When multiple links are aggregated, they act as a single logical link. This means that if one of the physical links fails, the rest can still maintain connectivity, ensuring high availability. However, without proper aggregation techniques, such as the Link Aggregation Control Protocol (LACP), these redundant links could create loops in the Layer 2 network, which would disrupt network communication and lead to broadcast storms. By utilizing link aggregation, switches can effectively and efficiently manage multiple connections without facing the pitfalls associated with network loops, thus ensuring robust data transfer and network stability.

The other options do not address the primary function of link aggregation in the context of preventing loops while using redundant paths. While higher bandwidth and cost allocations or security measures might relate to network architecture, they do not specifically capture the loop prevention function inherent in link aggregation.