How to apply the new settings in Linux

To apply the configuration that has been done, you must run the following:

For Redhat/Mandrake

#service network restart
or
#/etc/rc.d/init.d/network [startstoprestart]

For debian/Debian based Linux

#/etc/init.d/networking[startstoprestart]

For Hostname settings take effect, restart the whole operating system.