After installing CentOS you will wan’t to configure IP address. CentOS is  mostly used as Server. So you will want to give it a static IP address.  By default CentOS interface is configured to receive IP from DHCP  server. Here I will show you how to configure static IP address in  CentOS system.

Configure Static IP Address in CentOS

The following steps will show configuration of static IP address in CentOS machine.

  1. Files needed for network configuration are under /etc/sysconfig/network-scripts. So open the file with editor like nano or vi. Here I will use nano editor. After you start your server running CentOS enter root user credentials and get in. Type the command,
    # nano /etc/sysconfig/network-scripts/ifcfg-eth0
  2. You will see default configuration like this,
Configure Static IP Address in CentOS
  1. Now change the configuration to this,
IP Address Changed
  1. Then save the file, to save press ctrl+x to exit and press y for confirmation.
  2. Now restart the network services by issuing the command,
    [root@hostname~]# service network restart
  3. To verify the IP address issue the following command,
    [root@hostname~]# ifconfig
    You will then see following information,
Configure Static IP Address in CentOS
  1. After configuring IP address now let’s  configure DNS. Name server or DNS information is stored in different  file. The location is, /etc/recolv.conf. Again using nano editor to configure DNS information,
    [root@hostname~]# nano /etc/resolv.conf

By default, this file is empty, so enter at least one entry here,
nameserver 4.2.2.2
The name server IP address can be different depending on your  network scenario. I will use www.google.com. Now save the file and exit.  You can test the configuration by issuing ping command.[root@hostname~]# ping www.google.com

If you get the reply, you have successfully configured the IP address and DNS information.

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