Linux/IPv4

/etc/network/interfaces

• dhcp

iface eth0 inet dhcp

• static

iface eth0 inet static
    address 192.168.0.97   
    netmask 255.255.255.0  
    gateway 192.168.0.1
    dns-nameservers 192.168.0.1 10.10.0.2

netplan (Ubuntu 18.04+)

• static

network:
    ethernets:
        enp0s3:
            addresses: [192.168.1.2/24]
            gateway4: 192.168.1.1
            nameservers:
              addresses: [8.8.8.8,8.8.4.4]
            dhcp4: no
    version: 2