My Ubuntu Server has one physical interface
eth0. I want to assign 3 ip's (different subnets) to the server. I cannot use the default virtual interface creation tools like
ip addr add (e.g.
eth0:0) because for each of those 3 ip's I need to specify a default gateway. So, whether it is possible to have a bridge to which I can attach
eth0 ( and multiple tap or tun interfaces with ips that I want), but each of the virtual devices can connect to subnets accessbile over
Imagine I want 5 ethernet interfaces to connect to 5 different networks. But I can't afford to have 5 interfaces. So I buy an unmanaged switch, and connect cat5 cables from all the 5 networks to that switch and one port of that switch in connected to
eth0 of Ubuntu server. In order to deal with all 5 networks on Ubuntu server, I create 5 virtual interfaces that behave like physical interfaces (eth1, eth2, so on ..), that traverse through
eth0 and end up at the switch. I don't mind if all those seperate networks traverse through one unmanaged switch. But I want my Ubuntu server to treat those networks as if they are attached to 5 physical interfaces.