If you’re anything like my students or clients, you’ve probably heard the words “overlay” and “underlay” thrown around constantly in the world of SD-WAN. But in 2025, how much do you really understand about how these layers work—and more importantly, how they’ve evolved? Today, we’re […]
![2025 Guide: Overlay vs Underlay in SD-WAN – What’s Changed?[CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/06/Overlay-vs-Underlay-in-SD-WAN_networkjourney-1.png)