ip addr
apt install net-tools
ifconfig -a
# NAT
auto enp0s3
iface enp0s3 inet dhcp
# Internal network
auto enp0s8
iface enp0s8 inet static
address 192.168.100.10
netmask 255.255.255.0
/etc/init.d/networking restart
# NAT
auto enp0s3
iface enp0s3 inet dhcp
# Internal network
auto enp0s8
iface enp0s8 inet static
address 192.168.100.20
netmask 255.255.255.0
/etc/init.d/networking restart
все решаеться с помощью iptables + ip route