Hello I have download the minimal release of CENTOS 7 at this url link download ISO centos 7.x
All work correctly...the PING and the network is OK. I ping to external HO
First of all, I was able to fix this issue as mentioned above by using "dhclient". But you will have to run this command every time you reboot. This could be because your Ethernet is disabled and you have to enable it explicitly. Click here to see the reason. For a permanent fix I edited /etc/sysconfig/network-scripts/ifcfg-{YOURETHERNET} (In my case it was /etc/sysconfig/network-scripts/ifcfg-eth0) and changed ONBOOT=yes and boom!!!