change UNIX / Linux hostname, ip address, subnet mask dns and default gateway

The steps to change ethernet 0 ip configuration are:

Stop the interface:

       # ifdown eth0

Make the changes to the following files:

change the default gateway and hostname:
      # vi /etc/sysconfig/network

change the IP address and subnet mask:

     # vi /etc/sysconfig/network-scripts/ifcfg-eth0

change the dns settings:
     # vi /etc/resolv.conf

Start the interface:

   #ifup eth0