How to set a Static IP Address on CentOS-7

When you install the CentOS, IP Address set to dhcp mode. The configuration file for the network interfaces located at directory /etc/sysconfig/network-scripts. 

To list the network interfaces you need to type the following command:

~]$ ip a

DHCP Configuration for ens33 stored in file ifcfg-ens33 and the same is located at directory /etc/sysconfig/network-scripts/. It's look like below.

TYPE=Ethernet

PROXY_METHOD=none

BROWSER_ONLY=no

BOOTPROTO=dhcp

DEFROUTE=yes

IPV4_FAILURE_FATAL=no

NAME=ens33

UUID=d28f4e88-c167-4b78-b918-7b6e55c775e2

DEVICE=ens33

ONBOOT=yes

There are two method to Configure static IP address on ens33.

Method 1 : 

To configure a static IP address on ens33 using ifcfg file, edit file ens33-ifcfg using vi editor. File ens33-ifcfg is located at directory /etc/sysconfig/network-scripts/

~]$ vi /etc/sysconfig/network-scripts/ifcfg-ens33

Update file ifcfg-ens33 as per below

TYPE=Ethernet

PROXY_METHOD=none

BROWSER_ONLY=no

BOOTPROTO=none

DEFROUTE=yes

IPV4_FAILURE_FATAL=no

NAME=ens33

UUID=d28f4e88-c167-4b78-b918-7b6e55c775e2

DEVICE=ens33

ONBOOT=yes

IPADDR=172.16.16.2

PREFIX=16

GATEWAY=172.16.16.1

DNS1=8.8.8.8

Save and closed the file. Static IP Address configuration will be applied after network service restart or manually making interface down and up. You may use below command for network service restart.

~]$ systemctl restart network

To down and up network interface use below command

~]$ ifdown ens33

~]$ ifup ens33

Method 2 :

You may also configure static IP Address using NetworkManager text user interface (TUI) tool. nmtui, provides a text interface to configure networking by controlling NetworkManager.

If  NetworkManager-tui is not install, issue the following command as root:

~]# yum install NetworkManager-tui

To start nmtui, issue a command as follows:

~]$ nmtui

after using nmtui command, The text user interface appears. To navigate, use the arrow keys or press Tab to step forwards and press Shift+Tab to step back through the options. Press Enter to select an option and use Space bar toggles the status of a check box.

To set static IP address on ens33 using nmtui use below command.

~]$ nmtui edit ens33

Below windows will be open after above command