In order to use SDC managed packages from inside your organization usually it is not required to have internet access to install your packages, could you expand a bit more about your use case? Are you hosting your Delivery Hub? What kind of updates you are trying to get? Updates for a package? Or updates to a software pack?
So when I click the Get Packs link, a window opens with 2 tabs, Popular and Browse. I see MyEclipse 2015 Stable 3.0. When I click Install, I immediately receive an Error installing MyEclipse… message in the Notifications area. I was assuming this was an internet access problem, but it could be a permissions problem. The error doesn’t give me any details.
In order to give you a better response, could you please send to us the log files from your Admin Console install directory? Another issue could be the version of SDC you have installed, Do you know what version you are running? Perhaps trying to upgrade SDC?