CrushFTP supports high availability mode for Enterprise licenses.

This mode will allow for multiple servers to have *Replication* between the servers. A client is valid on all servers, as long as they stick to the server they started on.

A *CrushBalance* instance can be used for the load balancer, or your own F5 / AWS LB / etc. Using a LB gives active/active HA mode where using ServerBeat gives active/passive.

This can be combined with the *ServerBeat* feature to manage a Virtual IP between multiple machines. This way incoming access points to the VIP, and that VIP will move to a machine that is operational in the event the current machine using the VIP goes down.

Lastly the *DMZ* mode can be used placing a DMZ server being controlled by an internal CrushFTP server separated by a firewall allowing only outgoing initiated connections. Internal servers connect to one DMZ server, they cannot be cross linked, nor would that provide a benefit.

(Drawn via online.visual-paradigm.com.)