Slot 1 is reserved for the supervisor engine module, which provides switching, local and remote management, and dual Fast Ethernet uplinks. Slot 2 is available for a second, redundant supervisor engine, or any of the other supported modules. Slots 3-12 support any of the supported modules. The backplane provides the connection between power supplies, supervisor engine, interface modules, and backbone module. Supervisor Engine III is recommended for utilizing all three buses effectively.
Redundant operation is supported only with like supervisor engines.