A routing & switching learning platform built around the Raspberry Pi Compute Module 4, and the Microchip KSZ9477 gigabit ethernet switch.
These are the hardware design files. They're almost certainly terrible. Replicate this device at your own peril.
The Raspberry Pi Compute Module is installed with standard Raspbian. Configuration of the switching functions of the KSZ9477 are done via scripts communicating via the SPI bus. Configuration of routing functions are as per standard Linux methods.