[CentOS] No network on cloned CentOS 7 installation

Hi,

I have a few identical Dell Optiplex 7010 machines that I want to use for our school's computer room. I tried to clone these installations (like I did before on CentOS 5 and various versions of Slackware), but this time I ran into a problem.

Here's what I did.

1. Install one computer and zero unused hard disk sectors with dd.

2. Send the image to a local FTP server using G4L (Ghost4Linux).

3. Fetch the image on another computer.

4. Boot the new computer in rescue mode and change the hardcoded /etc/hostname to a new value.

Let me add that I removed all hardcoded MAC addresses from /etc/sysconfig/ifcfg-em1, which has only very limited information in it.

What else could cause the network to choke on a cloned installation?

Cheers,

Niki