Any number of Cornerstone servers can be configured to work in a clustered environment where each server shares the same database and file system to access files. Each Cornerstone server can also be configured to communicate with one or more DMZedge servers. 

The DMZedge server is a Windows service that listens on an internal port connected exclusively to a Cornerstone server.

DMZedge’s sole configuration option is the external IP address it will listen on for commands from Cornerstone. Cornerstone has a

DMZedge configuration option to determine what ports to listen on. For example, DMZedge can listen on port 80 for HTTP connections, 21 and 990 for FTP, or port 22 for SFTP. DMZedge will never listen on an external IP/port combination unless told to do so by a Cornerstone server. Therefore, most of the configuration is actually performed on the individual Cornerstone servers in the cluster rather than the DMZedge application.

In this mode, each DMZedge server routes traffic to a specific Cornerstone server rather than filling the first on the priority list before transferring to the second, etc. In this setup, multiple Cornerstone servers handle the load equally. Since multiple DMZedge servers listen on external IP addresses, this method requires a load balancer, such as F5’s big IP load balancer or Microsoft Clustering Services, to distribute connections to each of the DMZedge servers. You can configure the balancer to distribute connections to multiple DMZedge servers or, if no DMZedges are used, to multiple clustered Cornerstone servers which share a common database and file system.

For more detailed information, see the attached DMZ Network Diagram and DMZ-Cornerstone QuickStart Guide