Ethernet rules everything around us, a large proportion of our systems communicate to each other with ethernet somewhere in the line. And the fast pace race to the bottom for embedded systems means that almost all network equipment is smart to some degree these days.
One of the bright sides of this is that where there are smart things, there is generally Linux too. This is handy since Linux is practically eating the world and is familiar to many of us. At this point even lower end ethernet switches that used to be confined to turnkey chips are now also “smart” enough to be running Linux.
We are also in an interesting time where we have projects like the Open Compute Project that aim to make the hardware itself open between vendors. The resulting product from most Open Compute Project devices are “bare metal switches” that have the hardware to switch packets but no operating system to drive them. The operating system part for open switches (and participating non open design switches) is dealt with by a system called ONIE (Open Network Install Environment)
ONIE provides a mostly standardised boot environment that can be used to install other boot environments. From what it feels like the majority of users of ONIE use it to install Cumulus OS, a commercial debian based OS that is tuned for switches.