Switches can be stacked to improve reliability.

Stacking (iStack) is a key reliability technology for the access and aggregation layers. By connecting multiple switches into a single logical unit, the network gains device-level redundancy . If one switch in the stack fails, the other member switches continue to forward traffic. Furthermore, it allows for the use of Inter-device Eth-Trunk (link aggregation across different physical switches), which prevents loops without the need for STP, leading to faster convergence and higher network availability.