Many Windows administrators are familiar with the ipconfig
command line utility, which is used to get information about
network interface configuration and make changes to it. Linux
systems have a similar utility, ifconfig, which is a common part
of the day-to-day tool belt of most Linux sysadmins. There are
some distinct differences between ipconfig and ifconfig,
however, such as the fact that the DOS/Windows ipconfig does not
allow you to make changes to network configuration. In general,
you must be logged in as root or use sudo to make use of the
ifconfig utility on a Linux machine. The ifconfig utility can be
used either to simply get information about network interface
configuration or to change configuration, depending on what
options are used with the ifconfig command. Entering ifconfig at
the command line interface without specifying any options will
provide a fairly complete description of the current state of
all active network interfaces. For instance, on a machine with
hostname erebus, entering i