A lot of features in MPS require access to the internet. If you are working offline (for example, in an isolated environment), there are some aspects that you should keep in mind.
If you do not have internet access to view the online help, you can use the MPS Help plugin, which serves the help pages via the built-in web server for offline use.
By default, MPS is configured to check for updates automatically and notify you when a new version is available.
If MPS does not have HTTP access outside your local network, it will not be able to check for updates and apply patches. In this case, you have to download new versions of the IDE and install them manually as described in Standalone installation.
For more information, see Update MPS.
Usually, plugins are installed from the JetBrains Plugin Repository. However, you can set up a custom plugin repository in your local network and configure MPS to use it for installing and updating plugins.
Alternatively, you can download and manually install plugins from disk.
Version control systems
Most likely, your source code is under some sort of version control system (VCS). If a remote repository is not in your local network, and there is no internet access, MPS will not be able to communicate with the VCS. For example, if you are using Git, you will be able to commit your changes but won’t be able to push them to the remote repository or pull updates from it.
For more information about VCS integration, see Version control.
Even if you enable anonymous usage statistics, it will not be sent if there is no HTTP access outside your local network. Also, you can disable this feature entirely if you agreed at first and then changed your mind later.