View source for How to set static IP in Debian

 /sbin/ifconfig eth0 192.168.10.12 netmask 255.255.255.0 broadcast 192.168.10.255
 invoke-rc.d network restart


Configuration is in '''/etc/network/interfaces'''

'''Another Way'''

1) Edit the /etc/network/interfaces file

Set the static IP changing the network interface that you need (Example ETH0)

 # The primary network interface
 allow-hotplug eth0
 
 iface eth0 inet static
       address 192.168.0.30
       netmask 255.255.255.0
       network 192.168.0.0
       broadcast 192.168.0.255
       gateway 192.168.0.1

Save the file

2) Edit the /etc/resolv.conf file and add the DNS servers that you need

 nameserver 200.83.1.5
 nameserver 200.83.1.4
 nameserver 146.83.126.8
 nameserver 200.73.13.150
 nameserver 200.73.13.50

Save the file

3) Restart the network or your computer (I recommend to reboot the computer)