What are the four types of failover/load-balancing in SonicOS?

The four types of failover/load-balancing in SonicOS are indeed Basic Failover, Round Robin, Spillover, and Ratio.

Basic Failover refers to the simplest form of redundancy where one connection is active while the other is on standby to take over in case the active connection fails. This ensures that there is minimal disruption to network service.

Round Robin distributes traffic evenly across multiple connections, ensuring that no single connection becomes a bottleneck. This method is effective for load distribution among several WAN links, allowing for improved performance and resource utilization.

Spillover is a method where primary traffic is sent through one connection until it reaches a certain threshold, after which any additional traffic is directed to another connection. This is useful for managing bandwidth efficiently when you have varied traffic loads.

The Ratio technique allows administrators to set specific ratios for traffic distribution across multiple connections. This is especially useful in scenarios where certain connections may have differing capacities, enabling a tailored balance that aligns with performance needs.

These mechanisms ensure that network performance and reliability are optimized in various scenarios, reflecting the robust capabilities of SonicWall's SonicOS.