NAME
ifconfig -
configure network interface parameters
DESCRIPTION
The command
ifconfig is used to assign an address to a network
interface and to configure network interface parameters.
The ifconfig command must be used at boot time to define
the network address of each interface present on a machine;
it may also be used at a later time to redefine an
interface's address or other operating parameters. If no
option is specified ifconfig displays the current
configuration for a network interface. If an address family
is specified, ifconfig reports only the details specific to
that address family. Only the superuser may modify the
configuration of a network interface.
and some cut&paste
