auto enp7s0
iface enp7s0 inet static
     address 192.168.1.42
     netmask 255.255.255.0
     network 192.168.1.0
     broadcast 192.168.1.255
     gateway 192.168.1.1
     dns-search mydomain.lan mydomain.internal
     dns-nameserver 192.168.1.16 
     dns-nameserver 192.168.1.1
     
     up route add -net 192.168.1.128 netmask 255.255.255.128 gw 192.168.1.2
     up route add default gw 192.168.1.200
     down route del default gw 192.168.1.200
     down route del -net 192.168.1.128 netmask 255.255.255.128 gw 192.168.1.2