By default with either DHCOP or Static dual NIC does not work. I am pretty sure its static route issue on Ubuntu. When I set up Centos or Windows and both NIC enabled all is fine.
I am sure I am missing something here.
NIC1 10.2.1.220/24 GW 10.2.1.1 DNS 8.8.8.8
NIC2 192.168.1.220 GW 192.168.1.1 DNS 8.8.8.8
Only one NIC works at the time.