Use this whenever you want to enter a fixed ip address for your network cards

Usage

setip <interface> | -h
This command sets the ip information of your network card(s)
Without an argument, it assumes your network card is eth0
‘setip -h’ shows the help output
Here ‘s what  the command does:

setip eth1
Enter the IP-address for eth1: 10.0.0.1
Enter the subnet mask for eth1: 255.255.255.0
Enter the default gateway, <enter> for none: 10.0.0.254
Enter the IP-address of the DNS server you ‘d like to use, <enter> for none: 10.0.0.3

Setting ipaddress 10.0.0.1/255.255.255.0 on eth1
Setting default gateway to 10.0.0.254
Setting nameserver 10.0.0.3 in /etc/resolv.conf’

Also read the online manpage on this:

http://trinityhome.org/manpages/man8/setip.8.html