hi this mamun: Automatically detect a new network card in CentOS 6.x / RedHat Step by Step

Step 1 : Delete the persistent rules file

[root@ns1 ~]# cd /etc/udev/rules.d/

[root@ns1 rules.d]# ls -l
total 16
-rw-r--r-- 1 root root 316 Nov 5 17:19 60-raw.rules
-rw-r--r--. 1 root root 789 Mar 1 21:05 70-persistent-cd.rules
-rw-r--r-- 1 root root 422 Mar 8 22:24 70-persistent-net.rules
-rw-r--r--. 1 root root 53 Dec 8 2011 91-drm-modeset.rules

[root@ns1 rules.d]# rm -f 70-persistent-net.rules

[root@ns1 rules.d] ls -l

-rw-r--r-- 1 root root 316 Nov 5 17:19 60-raw.rules
-rw-r--r-- 1 root root 422 Mar 8 22:24 70-persistent-net.rules
-rw-r--r--. 1 root root 53 Dec 8 2011 91-drm-modeset.rules

Step 2 : Edit ifcfg-eth0:

[root@ns1 rules.d]# cd /etc/sysconfig/network-scripts/

Step 3 : Reboot System

[root@ns1 network-scripts]# reboot

If you change the NIC again, just repeat step #1 and # 3.

You can use this tool also

(This is not a GUI tool, its TUI tool, Text-based User Interface)

[root@ns1 ~]# system-config-network-tui

Type above command and press Enter

Then this screen will appear