RHEL 6 and 7 network installation

Hi,
I would like to know if it's possible to use a RHEL7 as http repository to install a remote server with RHEL6 where is already installed RHEL7

I don't have any problems with the same version (repository and target server) but with different one I'm unable to start the installation.

This is the scenario:
Https server: RHEL7 installed with RHEL6 iso mounted.
Target: RHEL 7 installed but that should be reinstalled with RHEL6 via http.

After the network boot I got these errors:
dracut-initqueue ln failed to create symbolic link /run/initramsfs/livedev: file exists
dracut-initqueue ln failed to create symbolic link /dev/root: file exists

the network connection works fine between the hosts, I see the httpd logs.

thanks in advance