Static IPv4 Configuration on CentOS 7

Introduction

How to configure Static IP Configuration on CentOS 7? Network configuration on CentOS 7 is made automatic and simple through the use of Network Manager. It manages network interfaces like Ethernet, WiFi, and Mobile Broadband devices, in addition to the primary network connection. Here you are going to quickly learn how to configure a network interface in etc/sysconfig/network-scripts/ directory using ifcfg files.

Prerequisites

• A VPS or  Dedicated Server with CentOS 7 installed.

Step 1: Create the file

The first step is to create this file /etc/sysconfig/network-scripts/ifcfg-eth0.
Here is how to step forward:

1)DEVICE=eth0
2)BOOTPROTO=none
3)ONBOOT=yes
4)PREFIX=24
5)IPADDR=192.168.2.203
6)Restart network service: systemctl restart network

In order to list network interfaces, type this command:

# ip a

or

# nmcli -p dev

You can see below the DHCP typical configuration for eth0 that is stored in /etc/sysconfig/network-scripts/ifcfg-eth0 file

DEVICE="eth0"
ONBOOT=yes
NETBOOT=yes
UUID="41171a6f-bce1-44de-8a6e-cf5e782f8bd6"
IPV6INIT=yes
BOOTPROTO=dhcp
HWADDR="00:08:a2:0a:ba:b8"
TYPE=Ethernet
NAME="eth0"

Step 2: Configuring an eth0 interface

There are two ways for this configuration. First Method In this method, you need to edit or create a new file by the name of ifcfg-eth0 in /etc/sysconfig/network-scripts/ directory

Here is how to do it:

# vi /etc/sysconfig/network-scripts/ifcfg-eth0

For static IP configuration, update or edit as the following:

HWADDR=00:08:A2:0A:BA:B8
TYPE=Ethernet
BOOTPROTO=none
# Server IP #
IPADDR=192.168.2.203
# Subnet #
PREFIX=24
# Set default gateway IP #
GATEWAY=192.168.2.254
# Set dns servers #
DNS1=192.168.2.254
DNS2=8.8.8.8
DNS3=8.8.4.4
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
# Disable ipv6 #
IPV6INIT=no
NAME=eth0
# This is system specific and can be created using 'uuidgen eth0' command #
UUID=41171a6f-bce1-44de-8a6e-cf5e782f8bd6
DEVICE=eth0
ONBOOT=yes

Save and close the file. The system will automatically calculate the network and broadcast address. Restart the network service using:

# systemctl restart network

Verify the settings

New IP

# ip a s eth0

New routing

# ip r

DNS servers

# cat /etc/resolv.conf

Internet connectivity

# ping -c 3 cyberciti.biz
# ping -c 4 google.com

Second Method The second method for configuring eth0 interface is the use of Network Manager nmtui command is used:

# nmtui edit eth0

Conclusion

Congratulations, you now know how to do Static IP Configuration on CentOS 7