I use a broadband connection, the ISP I use requires me to have a static IP address to login. At the same time, I also want my computer to be accessible to my friends on a LAN which has a different subnet.
Currently, it is not possible to configure multiple addresses for the same interface in Network Manager. I have to edit the /etc/network/interfaces file and add an extra interface called eth0:1, then manually restart networking to get two IP addresses for my requirement.