I've an single board computer, and I always want's that it works like a switch.
I have one Ethernet port, and one USB > Ethernet converter.
What's my idea?
The traffic is going in to the Ethernet port, and the traffic goes out to the second port, so I can monitor the full network usage of my home.
When I'm trying, and I connect to my computer, Windows says Unknown network, my computer does not get a IPv4 adress, he only detects the gateway correct.
Maybe I need a third Ethernet port for accessing SSH?
I've already enabled net.ipv4.ip_forward = 1 and test some command in iptables. I'm using Armbian Xenial.