How to configure IP's On Centos 7?

CentOS 7 uses NetworkManager daemon to manage primary network connection and other network interfaces, like Ethernet, WiFi, etc. This tool is easy to use and makes network configuration and operations as painless as possible. In the following article, we will configure a network interface using 'ifcfg' files located in /etc/sysconfig/network-scripts/ directory in a CentOS 7. NetworkManager is a software utility that aims to simplify the use of computer networks. NetworkManager is available for Linux kernel-based and other Unix-like operating systems.

In the following steps we will learn how to configure IPs on CentOS 7 using NetworkManager for both IPv4 and IPv6. Following are the steps covered

• Configuring IPv4
  • Step 1: Edit Network Configuration File
  • Step 2: Restart Network Service
  • Step 3: Verifying DNS Settings
• Configuring IPv6
  • Step 1: Editing sysctl.conf file
  • Step 2: Editing Network file
  • Step 3: Editing ifcfg-eth0 file
  • Step 4: Restart Network service

Steps to configure IPv4

Step 1

Open and edit the network configuration file for (eth0 or eth1) an editor to assign IP Address to eth0 or eth1 interface as follows.

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

Output:

The lines marked in bold are the important ones as you will have to modify them as per your needs.

Note: In case you find no file under /etc/sysconfig/network-scripts/ we need to create one. Create a file named /etc/sysconfig/network-scripts/ifcfg-eth0 using a VI editor and add the above content in the file. Press Esc and then :wq (to save and exit)

Step 2

Now, Restart network service

# systemctl restart network

Let us now verify the IP settings

# ip a s eth0

Output

Step 3

Verifying DNS server settings

# cat /etc/resolv.conf

Output

The last step to verify that you have successfully configured the network on your CentOS machine is to check if you can reach any site. You can simply use the "Ping" command followed by the web address (e.g. google.com) and you will get the results

Steps to configure IPv6

IPv6 possess certain features that are superior to IPv4 address in terms of efficient routing, directed data flows, simplified network configuration, security and much more.

Following are the steps to assign IPv6 address on your server

Step 1

You need to edit sysctl.conf file. Using VIM editor open the file to edit it.

# vim /etc/sysctl.conf

Add the following two lines at the end of the file

Save and exit using "esc + :wq"

Step 2

Edit the network file using VIM editor which is located under /etc/sysconfig/

# vim /etc/sysconfig/network

Add the following line at the end of the file.

Save and exit using "esc + :wq"

Step 3

Now we will edit the ifcfg-eth0 file under the path /etc/sysconfig/network-scripts/

# vim sysconfig/network-scripts/ifcfg-eth0

Append the following lines to the file,

Save and exit using "esc + :wq"

Note: Kindly replace the IPv6 address and default gateway with the one provided to you.

Step 4

Now you may restart the network service to bring all the changes into effect

# /etc/init.d/network/restart

You can test the connection by pinging any website (e.g. www.google.com)