What happens if you uncomment the 2 lines in /etc/network/interfaces
#auto eth1 #iface eth1 inet dhcp
to be
auto eth1 iface eth1 inet dhcp
What happens if you uncomment the 2 lines in /etc/network/ interfaces
#auto eth1
#iface eth1 inet dhcp
to be
auto eth1
iface eth1 inet dhcp