The espressobin has three ethernet ports. In Ubuntu Armbian, left to right (looking into the ports), they're called "lan1", "lan0", and "wan".
The weird thing is that you can't bring them up until you've *first* brought up eth0, which is not associated with a physical port. This causes all kinds of havoc trying to use /etc/network/interfaces/, because it takes a couple of seconds for eth0 to come up, in which time the other interfaces have already failed.
1) What is this mysterious eth0?
2) My attempts to bridge lan0 and lan1 from .../interfaces have failed. Got an example you can give me?