Does unRAID need Internet access?
The unRAID server software does not need any Internet access. Of course, you will need Internet access from another desktop to download the software, and to read the unRAID forums and this Wiki! If you choose, there are a few benefits to providing limited Internet access to your unRAID server. For one, unRAID supports NTP, the Internet time service, so if you enable the NTP service, your server will keep very accurate time. For another, expert unRAID users have created addons for unRAID, that can provide email notifications, torrent support, etc. All of these benefits are completely optional. See also this.