How to change hostname or FQDN in CentOS and Redhat

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How to change hostname or FQDN in CentOS and Redhat

In this tutorial we will learn about,how to change Hostname or FQDN in CentOS and Red Hat.
The method is applicable to all Red Hat based operating system. I have described about difference between hostname and FQDN which you can read from this post (The post is written on how to change hostname in Ubuntu,read the theory).

Step 1: Edit the /etc/hosts file and give IP Address,FQDN name and Server name

 #vi /etc/hosts
        ipaddress_of_system server1.sharadchhetri.com server1

Step 2: Edit /etc/sysconfig/network file ,give HOSTNAME as machine name i.e server1

         # vi /etc/sysconfig/network
         NETWORKING=yes
         HOSTNAME=server1

Step 3: Restart the network service.

         /etc/init.d/network restart

Now check the hostname and FQDN with command called hostname and hostname -f respectively.

#hostname
 server1
#hostname -f
 server1.sharadchhetri.com

Note: There is another method through which you can change the hostname but generally it is not so much preferable.

The command is 

sysctl kernel.hostname                      (It will show the current hostname)
sysctle kernem.hostname Give_hostname        (It will set the hostname)

Related posts:

  1. How to set hostname and FQDN on CentOS 7 and RHEL 7
  2. Set hostname and FQDN in Ubuntu without reboot
  3. How to change hostname in Ubuntu 12.04 and 12.10 without system restart
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  5. How to install mysql server in RedHat and CentOS
  6. How to reset forgot root password in CentOS 6.x and Redhat 6.x
  7. How to change login banner message in GUI mode in CentOS 6 or above version.
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6 thoughts on “How to change hostname or FQDN in CentOS and Redhat”

  1. What software have you encountered which is sensitive to whether the hostname is set to the FQDN or short name?

    Reply

  2. I am confused if the IP address is the internal LAN address such as 192.168.1.x, or is it the external public WAN IP?

    Also the host file currently contains the following which is slightly confusing:

    127.0.0.1 localhost.localdomain localhost.localdomain localhost 4 localhost4.localdomain4 localhost::1 localhost.localdomain localhost.localdomain localhost6 localhost6.localdomain6 localhost

    Thanks for the great info! Sometimes it is hard to find info on the simpler items.

    Reply

  3. thanks man, some time the easy thinks make big problems, ldap, zimbra problems for bad /etc/sysconfig/network config.

    really apreciated.

    Reply

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