Which algorithm does SD-WAN use for traffic distribution that doesn't match any established rules?

In SD-WAN, when traffic doesn't match any established rules, the default behavior is to ensure that all traffic from a specific source IP to a specific destination IP is consistently directed to the same interface. This method helps maintain session persistence and integrity, ensuring that packets belonging to the same connection are sent over the same path.

This behavior aids in minimizing disruptions that could occur with the reordering of packets, which is crucial for applications that are sensitive to latency and jitter. By funneling all traffic for a particular session through the same interface, the network provides a more stable experience for end users, particularly for time-sensitive applications like VoIP or video conferencing.

Other methods like round-robin scheduling or even distribution can lead to packet sequencing issues and connection drops if packets are delivered over multiple paths. Therefore, maintaining a consistent path for traffic flows that do not have explicit rules is the reason behind the choice being correct.