Edit the /etc/network/interfaces file and enter the relevant IP data to permanently add a secondary IP address to an Ubuntu machine. Check the IP address that was just added: # eth0 ifconfig Encaption of the link: Ethernet HWaddr 08:00:27:98:b7:36 inet addr:192.168.56.150 Bcast:192.168.56.150 HWaddr 08:00:27:98:b7:36 inet addr:192.168.56.150