We recently upgraded one of our Supervisor 2 Engines on our Catalyst 6509 Switch to a Supervisor 720. We thought it would be a simple upgrade but quickly realized it wouldn't be that simple.

Model: WS-C6509 Catalyst Switch w/ WS-SUP720 Supervisor Engine

Compatible with the following chassis:
Cisco 6503, 6503-E, 6506, 6506-E, 6509, 6509-E, 6509-NEB, 6509-NEB-A, 6513
Cisco 7603, 7606, OSR-7609, 7609, 7613

We installed the SUP720 in a Catalyst 6509 Switch with a standard WS-CAC-1300W power supply and a standard FAN tray.

Upon boot, the supervisor engine ran diagnostics and soon after diagnostics were completed failed due to the FAN tray not being compatible. A quick glance at Cisco.com and we realized that the FAN tray would need to be upgraded to a high-speed fan.

We installed the following:
WS-C6K-9SLOT-FAN2 Cisco Catalyst 6509 high-speed fan tray

We booted the unit up again and this time the diagnostics resulted in an error having to do with the power supply not being compatible with the high-speed fan tray. We now realized that the high-speed fan tray requires a WS-CAC-2500W power supply.

We installed the following:
WS-CAC-2500W 2500W AC Power Supply

At this point the SUP720 worked fine and we were able to complete the upgrade.

Summary: A WS-SUP720 on a Catalyst 6509 Chassis requires an upgrade to both the FAN tray and Power supply.