About the RSN.ini File
The RSN.ini file is essential to server-based worksharing. This file provides the list of Revit Server Hosts that are available to a particular Revit application workstation, a Revit Server Accelerator, or a Revit Server instance with the Admin role enabled.
Best Practices: Revit Server Deployment
Because each instance of Revit Server can have any or all of 3 possible roles enabled (Host, Accelerator, and Admin), there are many different ways you can configure your Revit Server network to meet your server-based worksharing needs.
Install and Configure Revit Server
The basic procedure for installing an instance of Revit Server is the same regardless of whether that instance will host central models, cache local models, run the Revit Server Administrator, or perform some combination of these roles (Host, Accelerator, and Admin). The installer prompts you to specify which roles you want to be enabled.
Install Different Versions of Revit Server on the Same Machine
You can install the latest release of Revit Server on the same machine where previous versions are installed, and you can also install a previous version of Revit Server on the same machine where you have installed the latest release of Revit Server.