I have to install redhat without a direct access to the internet. I have now installed Redhat 5.4 and would like to upgrade to 5.6. I have copied the content of the iso image to $INSTALLDIR - how do I update now. How can I register the server when I have a valid licence number? I have seen this questionquestion, but it does not answer the registeration part / I tried rhn_register, but it requires an Internet connection.
As far as I know, registering with RHN requires an Internet connection in order to send the machine's hardware information for profiling and contract compliance. There is an RHN Satellite server available that can be used in detached mode, for organizations that have stringent security requirements. If the server absolutely must be kept offline, you should speak with your channel partner for details about that option.
Some info on the RHN Satellite: https://www.redhat.com/red_hat_network/faq/
In order to perform the update without access to the internet, the easiest way is to create a local yum repository.
Some info on creating a local yum repository: https://access.redhat.com/kb/docs/DOC-7228