iface eth_main_file_1 inet static
    address 10.1.20.10
    netmask 255.255.255.0
    dns-nameservers 8.8.8.8 8.8.4.4 4.2.2.2
    dns-search mydomain.com myotherdomain.com

source interfaces2.txt
source interfaces2*.txt
source no_interfaces*.txt

iface eth_main_file_2 inet static
    address 10.1.20.10
    netmask 255.255.255.0
    dns-nameservers 8.8.8.8 8.8.4.4 4.2.2.2
    dns-search mydomain.com myotherdomain.com
