How to set hostname in fedora core 16

We have three way to change the hostname in Fedora core 16


1) Vim /etc/hosts, edit and add "test123" in last



127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4 test123
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6 test123


2) Vim /etc/sysconfig/networks, change hostname

 NETWORKING=yes
HOSTNAME=test123
~                             

3) Use command hostname 

  set hostname test123


4) Reboot the machine

the machine should display the new hostname "test123"