You should not be using Subscription Manager to register any of the lab systems to Red Hat. Yes, Subscription Manager takes your Red Hat account information (Username/Password), however, that will mess up your lab environment. The classroom is intended to run in disconnected mode. Furthermore, the workstation machine has its repository coming from the classroom server and the other systems in the lab environment are meant to be subscribed to your Satellite server. Using subscription manager to register any of these systems could break the lab environment and result in unintended consequences.
Usernames and passwords for the classroom environment are:
student/student
root/redhat
admin/redhat (for the Satellite Web console)
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