Creating a Local Yum Repository(Not connected to Internet)---FTP

I am trying to mirror/create a Redhat enterprise yum repository(That will Not be connected to the Internet). But continuously update the repository Not connected to the internet.

With the Internet connected server.....Using Redhat help "How to create a local mirror of the latest update for Red Hat...without using Satellite server" encountered 2 issues
I have reposync the rhel-7-server-rpms. 1. Followed the above to the second >> createrepo -v /var/ftp/pub/repo-id/ -g comps.xml (Error groupfile...comps.xml cannot be found)
2. What is the best way mirror/transfer the Internet connected rpms(above) to my network repository(NOT connected to the internet)?