I have been working with SCCM 2012 a lot lately and I run across a tool that has become invaluable for me.
Distribution Point Job queue manager
This is a part of the Config manager toolkit. What this allows you to do is view the status of the distribution manger on your primary site. If you are troubleshooting content distribution this tool can be invaluable.
if you want a better overview of the tool take a look at this post on technet.