After installing RHEL/CentOS 7 minimal, You may not able to connect network in that machine. This will happen because Ethernet interfaces are not enabled by default.
First, type “nmcli d” command in your terminal for quick list Ethernet card installed on your machine:
Now choose you network interfaces and click “Edit”
Choose “Automatic” in IPv4 CONFIGURATION and check Automatically connect check box and press OK and quit from Network manager.
Reset network services:
service network restart