How to register Clone RHEL to RHN
In order to register a Clone RedHat Enteprise to RHN and avoid having duplicate entry, you need to reset the unique SystemID of your Clone RedHat Enterprise.
To do so, you will need to remove the file systemid which contain a unique identifier for your machine that RedHat RHN use:
#rm -f /etc/sysconfig/rhn/systemid
You now need to run the rhn_register command to register your server to RHN as a new server.
To register the system, run either of the following commands:
# rhn_register
or
# rhnreg_ks --username=<RHN or Satellite login> --password=<RHN or Satellite password> --force
Source:
https://access.redhat.com/solutions/8036
The accepted answer on this link:
http://www.experts-exchange.com/OS/Linux/Distributions/Q_26408512.html