Virtual Interfaces Question
 

I have been researching virtual interfaces and was wondering why do people use them? If your machine has only 1 network card say eth1 why would you create a virtual interface like eth0:0

Why do people use this?

Thanks

Well if you only have one ethernet card then you would not have an eth1, only eth0. You might want to have a machine to respond to two addresses, e.g. you have bought two IP addresses from your ISP and want to route them to the same box for different functions.