Cisco LAN fault-tolerance system - diagram

"Fault-tolerant computer systems are systems designed around the concepts of fault tolerance. In essence, they have to be able to keep working to a level of satisfaction in the presence of faults. ...
Most fault-tolerant computer systems are designed to be able to handle several possible failures, including hardware-related faults such as hard disk failures, input or output device failures, or other temporary or permanent failures; software bugs and errors; interface errors between the hardware and software, including driver failures; operator errors, such as erroneous keystrokes, bad command sequences, or installing unexpected software; and physical damage or other flaws introduced to the system from an outside source." [Fault-tolerant computer system. Wikipedia]
The computer network diagram example "Cisco LAN fault-tolerance system" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Cisco Network Diagrams solution from the Computer and Networks area of ConceptDraw Solution Park.