Hi. I've got a wired network connection and if I'm using network manager (hereafter "NM") everything works fine except for the hardware address (it doesn't change). I'm thinking of using /etc/network/interfaces. So, I added some code and it looks like this:

auto lo
iface lo inet loopback

auto eth1
iface eth1 inet static
address #corresponding value
netmask #corresponding value
gateway #corresponding value
hwaddress #corresponding value

After restarting networking I get the following message:

*Reconfiguring network interfaces...
#here some help code appears
Failed to bring up eth1.

The default interface that works with NM is eth0. Please advise on how to handle the problem.