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Home » Networking

Red Hat: Changing Hostname and IP

Submitted by on August 31, 2011 – 1:47 pm3 Comments

Changing hostname and IP is frequently required when a server is being moved from testing or development to production. The process is a fairly simple one, but steps must be performed in a certain order to avoid complications. Before making any changes you must confirm that the new IP is available and that your server – physical or VM – can access the new network. You will also need to have console access to the server.

For our example, we are changing hostname from srv-dev-01.krazyworks.com to srv-prd-01.krazyworks.com. The IP address is changing from 192.168.102.17 to 192.168.112.17 on interface eth0. The first step is to create backups of the files we are going to modify:

Now open the /etc/hosts file and modify/add a line with your server’s new IP, fully-qualified DNS name, and short hostname:

The next step is to edit the configuration file for the eth0 network interface: /etc/sysconfig/network-scripts/ifcfg-eth0. At the very least, you will need to check the IP address, the netmask and the MAC address of the network interface card.

Now we need to modify /etc/sysconfig/network to change the hostname and default gateway information:

As the final step, you may run the hostname command to set the hostname for the current session and restart network services:

Make sure you can ping the default gateway, the DNS server and any other critical servers (NIS, LDAP, NFS, etc.) At this point it would be a good idea to reboot the server to make sure there are no unexpected issues with the hostname change.

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  • mavis24

    I am working as a broadband internet field engineer. In windows 98 or xp i can easily put ip, subnett, dns, gateway in my network places>view network con.>local area connection>properties>TCP/IP.but i dont know where i put ip address in LINUX, please help me step by step to give u best answer.

  • Victoria T

    I have an internet connection with a dynamic ip address, and the usb modem is attached to my wifi router, i want to host my website from vmware, from linux servers, i have installed ubuntu server, centos, red hat and more, but how do i host the website from these? I have a dynamic ip address and I dont want to open port 80 for my whole computer, only for the virtual machine, most preferably i will use ubuntu server, please give me proper instructions, and my isp wont give me a static ip, and i cant change my isp as well.

  • Alina Elliott

    I am in college and wanted to know if my IP address on the school computers would be different than my own Macbook. I use the same log in info to connect to wi fi that I use to access a school computer, thanks!