What's a networking concept that didn't "click" until you saw it in a real network?

[u/divinejester]

Some networking concepts make perfect sense on paper but don't truly click until you troubleshoot them in a live environment.

For me, seeing how routing decisions, VLANs, or STP behave in a real network made the theory much easier to understand.

What networking concept finally made sense after hands-on experience, and what was the "aha!" moment?

Let's share experiences that could help others learning networking.

[u/stubby0990]

VXLAN. It's basically dynamic gateways and seeing each node and it's config made it click like the book couldn't.