ifconfig in Linux

# ifconfig eth0 down                         Shutdown ethernet link
# ifconfig eth0 up                           Start ethernet link
# ifconfig                                   Display connection details
# ifconfig eth0 hw ether 0:0:0               Spoof a MAC address
# ifconfig eth0 10.10.28.5                   Spoof a IP address
# ifconfig eth0 netmask 255.255.0.0          Change the netmask