SolidWorks communicate to the internet all the time. Most users may not even realize just how often this happens. There is a Community heading under the SolidWorks Resources tab in the task pane. This area has links to the Customer Portal, User Groups, SolidWorks forum. It also has an RSS feed labelled Technical Alerts & News. I’m not sure how often this feed is refreshed by SolidWorks. There is an option to turn it off if it happens to be unwanted or generating errors (due to the lack of Internet access).
In Tools pulldown>Options>System Options>General there is a toggle setting labelled Show latest news feed in task pane. Simply uncheck its box to turn off SolidWorks’ RSS feed reader.
Another similar option that some may wish to turn off is just underneath the RSS reader toggle, labelled Enable performance feedback. This feature is needed once in awhile to help SolidWorks Corp understand why SolidWorks crashes. However, I think most users would rather just have this turned off.
Unless a computer has serious limitations, neither of these settings should cause performance or stability issues if turned on.
(Thanks to Charles Culp for bring identifying these settings in a recent SolidWorks Forum discussion.)