Now I have to guess a little - not running Ubuntu myself but pure Debian.
If you don't have a network-manager (there are several but I think Ubuntu's is actually named network-manager) then a Debian-system uses /etc/network/interfaces for nic-configuration.
However, I do believe Ubuntu uses a special manager for networking (as mentioned) this means you have to configure your nic's through that.
Look at your post: you have configured eth0 & eth1 in /etc/network/interfaces, but ifconfig shows eth1 & eth2.
Quote:
It seems that taking manual control from DHCP is really hard
It also seems that having 2 nic in 2 nets is hard.
|
Nope. Wrong.
Well, of course anything you don't master might seem 'hard' - but for you, here, I think all you need is understanding in how your distro handles networking. Once you get configuration right it will just work.
---
So to make it clear: Checkout Ubuntus network-manager and configure your nic's there. Forget about /etc/network/interfaces it is not read.