未修改过的/etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
auto eth1
iface eth1 inet dhcp
auto eth2
iface eth2 inet dhcp
auto ath0
iface ath0 inet dhcp
auto wlan0
iface wlan0 inet dhcp
修改过的/etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 192.168.200.99
netmask 255.255.255.0
gateway 192.168.200.100
auto eth1
iface eth1 inet dhcp
auto eth2
iface eth2 inet dhcp
auto ath0
iface ath0 inet dhcp
auto wlan0
iface wlan0 inet dhcp
启动项 /etc/init.d/networking
重启 sudo /etc/init.d/networking restart
转自：http://ubuntuchangeip.jiaogen.com/2010/06/18/ubuntu%E4%B8%8B%E4%BF%AE%E6%94%B9ip%E5%9C%B0%E5%9D%80/