Ifconfig
From Noah.org
Set static IP
These settings are lost on reboot. This is just for a temporary config.
# ip route add default via 192.168.0.1 # ifconfig eth0 192.168.0.2 netmask 255.255.255.0
Virtual Interfaces
Add virtual interfaces is trivial in Linux. Just add a number to a real interface (in this example, eth0). So here we configure eth0:1:
# ifconfig eth0:1 192.168.0.3 netmask 255.255.255.0
Delete an interface
Use the 'down' command:
# ifconfig eth0:1 down