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Fan direction in ASA's


I'm using a couple of ASA5510's since a few years in a few datacenters, and I wonder about the following:

Usually the ASA's are positioned with the connectors facing to the back of the 19" cabinets, so one can easily connect the device to other networking-hardware. In many datacenters nowadays, cold-coridors are used, which results in a forced airflow through the cabinet, which is empowered by the fans in the servers itself. But the ASA's are permanently blowing air in the opposite direction, and are also taking the air from the part of the cabinet where the air is as hot as it gets.

Does anyone know if it's a good practice to open up the ASA and flip the fans 180 degrees to solve this? Or am I just worrying too much?


Just rack the ASA the propper way

Hi Bro

I understand your concern. If you must know, Cisco ASA releases much more heat than Cisco PIX. Cisco TAC has confirmed this, but I can’t recall the Cisco TAC case number. In fact, another person in this community has confirmed this too

Hence, your equipment rack has to be well ventilated and ensure the chassis top panel is properly fasten/secured. The Cisco ASA's chassis is designed to allow cooling air to flow effectively within it. Furthermore, baffles can help to isolate exhaust air from intake air, which also helps to draw cooling air through the chassis. The best placement of the baffles depends on the airflow patterns in the rack. The current fan's position are designed to suck cool air in and blow it through the chassis. Do not reposition the fan. Repositioning the fan is gonna spoilt the hardware.

Just to share with you, most of the datacenters that I have been to, only the rear rack door is dismantled, to further supplement the proper air flow IN/OUT of the network equipment racks. This isn’t the best recommended physical security as per Cisco’s best practice, but as long as you’ve proper physical security to the main door of the datacenter, I guess that should do it for now :-)

After all, not all companies (especially small to medium size) out there can afford to spend huge sum of good money to purchase expensive well designed top notch equipment racks such as APC, Great Lakes, Chatsworth, SharkRack, Rittal etc. that allows them to have equipment racks with front and rear door closed 24/7 365 days, a year.

P/S: If you think this comment is helpful, please do rate it nicely :-)


Warm regards,
Ramraj Sivagnanam Sivajanam

You shouldn't leave your racks open because of an ASA. You can always fix the rack mount brackets to the ASA on the opposite side.

The rear of the ASA is the OPPOSITE side to where the power connection is. i.e. the rear is where the exhaust fans blow out air.

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