5 Steps to Setup Static IP And FQDN to CentOS Machine

Most of the when we start to setup any kind of cluster (for Hadoop, Spark etc…) from scratch, we as a beginner often  face certain problems while performing steps (like setup Static IP address or setup FQDN) after installation of Linux flavour OS on our VM or Machine. There are very less forums where you can get all of these bazics steps together along with full understanding. Here I have tried to explain you the process of setting up static IP address and FQDN (Fully Qualified Domain Name) in 5 steps. All of these steps are tested on VM/Machine available straight after minimal installation of CentOS 6.4.

So here are the steps after you login with your root user on your machine.

Step 1: Changing Ethernet Interfaces to Configure Static IP address

First thing is to change configuration of Ethernet Interface in /etc/sysconfig/network-scripts/ifcfg-ethX (CentOS 6 onwards) or /etc/sysconfig/network-scripts/ifcfg-emX (Prior to CentOS 6). Your current configuration would look like below.

$ vi /etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1		# This value should be same as file postfix (i.e eth1 for ifcfg-eth1)
HWADDR=08:00:27:87:7B:70
TYPE=Ethernet
UUID=ce2a0c5f-fee6-44e1-89e8-bc68162a9a04
ONBOOT=no
NM_CONTROLLED=yes
BOOTPROTO=dhcp

We need to do following changes to make setup Static IP.

Update:

BOOTPROTO=static 	#To use Static IP as a protocol
ONBOOT=yes		#To activate device on boot time

Add:

IPADDR=192.168.1.10	#Static IP Address (should not conflicted with any other IP in network)
GATEWAY=192.168.1.1	#Network Gateway 
DNS1=8.8.8.8		#Public DNS of Google for internet access
NETMASK=255.255.255.0	#Netmask Value
BROADCAST=192.168.1.255	#Broad cast IP address

Step 2: Setup FQDN (Fully Qualified Domain Name)

After updating Static IP address we need to map that IP to domain name in /etc/hosts file by adding one entry with IP address FQDN and hostname.

$ vi /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.1.10 master.backtobazics.com master

Step 3: Network Configuration

Add below configuration in /etc/sysconfig/network file.

$ vi /etc/sysconfig/network
NETWORKING=yes		#YES if to configure network
HOSTNAME=master	#Hostname without domain name

 Step 4: Restart Network Service

Now we are done with our configuration and in order to make those changes effective we need to restart network service using below command.

$ service network restart
Shutting down interface eth1:                              [  OK  ]
Shutting down loopback interface:                          [  OK  ]
Bringing up loopback interface:                            [  OK  ]
Bringing up interface eth1:                                [  OK  ]

 Step 5: Verification

The final step is to verify the changes using various commands.

  • Command to verify IP Address
$ hostname –i
192.168.1.10
  • Command to verify Hostname
$ hostname
master.backtobazics.com
  • Command to verify Domain Name
$ dnsdomainname
backtobazics.com

I hope all steps are clear enough to understand. Know more about next steps of setting up a new cluster in my further posts.

 

One thought on “5 Steps to Setup Static IP And FQDN to CentOS Machine”

  1. Hi,
    when i try to update the statick ip with command /etc/sysconfig/network-scripts/ifcfg-eth2 i am getting the blank page.

    Thank you

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