Step :- 1
Remove the ip address using below Command.
#ip address delete 192.168.0.102/24 dev eth0:2
Step :- 2
Remove the alias device created from devices folder.
#rm -f /etc/sysconfig/networking/devices/ifcfg-eth0:2
Step :- 3
Remove the main config file
#rm -f /etc/sysconfig/network-scripts/ifcfg-eth0:2
then check the “system-config-network” command there is no eth0:2 any more.