Getting I.P address of Ubuntu Server running in Virtual Box
Solution 1:
You don't have an IP address because you have not configured one. To do so you need to edit /etc/network/interfaces. If you want one to be obtained automatically, add eth0 to the auto line in the file, and add a new line for it that reads iface eth0 inet dhcp. You can then reboot or run sudo ifup -a to bring up the interface and obtain the IP address. See man interfaces for more information.
Solution 2:
I used "About This Computer..." menu item to get computer's name and later ping command to get its IP. I hope this will be helpful for you.
