This package is used by debian-installer to configure the network. The purpose
1. configure the network for the currently running kernel so that the base
system can be retrieved from the internet or a local mirror.
2. write configuration files so that when the machine reboots into the full
debian system the network is brought up automatically.
netcfg is written specifically for the debian-installer and probably won't work
as expected is you try to run it on a full Debian system. If you want
something for a full system, take a look at etherconf or ppp-config (eventually).
Currently static and dhcp configuration is supported.