This should also work for command line IP address changes to Linux:

edit the file /etc/network/interfaces

Change:

auto eth0
iface eth0 inet dhcp

To:

auto eth0
iface eth0 inet static
address 172.16.40.10
netmask 255.255.0.0
network 172.16.0.0
broadcast 172.16.255.255
gateway 172.16.2.47
dns-nameservers 172.16.2.4 172.16.2.15

Restart neworking

sudo /etc/init.d/networking restart