I am reading an O'Reilly book, "TCP/IP Network Administration", and there is something said which does not make any sense to me. Is there someone who might be able to explain the meaning behind this: TCP/IP CH 6 - Configuring the Interface "When networking protocols work only with a single kind of physical network, there is no need to identify the network interface to the software. The software knows what the interface MUST be; no configuration issues are left for the administrator." This doesn't make sense to me, because if I set up a machine with an ethernet card in it, I still have to configure that interface. I tell it what IP address to use. Even if I only have one ethernet card, and no other interfaces installed, this is so. Why would they say something like this? What do they mean that if there is only one physical interface it doesn't need to be configured?