Starting with the Data Plane: VLANs and VRFs

In the beginning was the network. The network was formless and empty, the darkness brought by collisions was over the surface of the deep, and the spirit of the Netlord hovered over the all-encompassing broadcast domain.

And the Netlord said, “Let there be routers,” and there was hope for frames and packets. The Netlord saw that routers were good and that they separated broadcast domains, each of them being named a subnet.