May 09 06:20 2016, Tony Langdon wrote to Markus Reschke:
TL> Not all routers require two Ethernet interfaces. a VPN/tunnel TL> router, for instance doesn't. The second interface is a tunnel device TL> (tunN in Linux).
I wouldn't be happy with running WAN and LAN over the same interface. Or where should the private traffic of the VPN tunnel be routed to?