M10i Router Cooling System
The M10i router cooling system consists of two fan trays, located along the left and right side of the chassis that provide side-to-side cooling. The fan trays house eight fans that draw room air into the chassis to maintain an acceptable operating temperature for the Routing Engine, Physical Interface Cards (PICs), Compact Forwarding Engine Board (CFEB), and other components. The fan trays connect directly to the router midplane. If a single fan fails, the remaining fans continue to function indefinitely (see Figure 107).
For proper airflow, the primary fan tray should be installed in slot 1 (the left slot looking at the chassis from the rear) and must be installed for proper cooling at all times. The redundant fan tray, if present, should be installed in slot 0 on the right. This fan tray provides additional cooling and redundancy.