to set your ip, in you command line
# system-config-network
Then you will be asked which eth you would like to modify. Select the eth then press enter. Set in the data needed and select OK then you will be back at your previous page, finally select quit. Dont restart the network yet.
The second step is to set your DNS. you can use vi, mine is nano
# nano /etc/resolv.conf
Then enter your DNS eg.
nameserver 192.168.1.1
If there is other text in it, remove it then replace it with a format mentioned above. dont forget to make a backup. If you are setting up multiple DNS, you may want to read the previous post I made just before this.
Finally restart the network
# service network restart
Then check if your settings work ny using ping ie.
# ping wwww.google.com
Thats it for this post. :D cheers