Though hidden from view in an actively running system, the midplane is the focal point for all connectivity within the M1000e modular system. The midplane is a large printed circuit board providing power distribution, fabric connectivity, and system management infrastructure. Additionally it allows airflow paths for the front-to-back cooling system through ventilation holes. As is requisite for fault-tolerant systems, the M1000e midplane is completely passive, with no hidden stacking midplanes or interposers with active components. I/O fabrics and system management are fully redundant from each hot-pluggable item. The system management Ethernet fabric is fully redundant when two CMCs are installed, with two point-to-point connections from each server module.