Can't register RHEL7 system. Network error.

Hi,

I'm a newbie working with Virtual Machines and Red Hat. I did the register in the Red Hat website, downloaded and installed RHEL7 in one Virtual Machine and when I tried to use the yum command it says "This system is not registered to Red Hat Subcription Management". I assume the system is this new OS installation in my computer and I need to register it to be able to have access to red hat commands, let me know if I'm wrong.

To register I tried to follow the instructions in https://access.redhat.com/solutions/253273, but when I do the command "subscription-manager register --username --password --auto-attach" it returns:

"Registering to: subscription.rhsm.redhat.com:443/subscription
Network error, unable to connect to server. Please see /var/log/rhsm/rhsm.log for more information"

I checked the log file and it shows the error "Name or service not known".

My DNS settings in /etc/resolv.conf is correct according to https://access.redhat.com/discussions/719723?tour=8 and my prefix in /etc/rhsm/rhsm.conf also seems to be correct according to https://access.redhat.com/solutions/3002811 since in my case the prefix is "/subscription".

I tried to ping subscription.rhsm.redhat.com, www.google.com and other addresses, but it always returns "Name or service not known".

I also tried to follow the correction at https://access.redhat.com/solutions/117723, but the same error continues.

Thanks for any help.