Cisco Support in Thailand After End of Life

Two Variants That Look Identical

Cisco switch power supplies and fan trays are supplied in two airflow variants that move air in opposite directions through the chassis. They share a form factor, they fit the same bay, and the unit powers on and reports healthy either way. The only difference is which end takes air in — and that difference determines whether the device cooperates with the room or fights it.

The Wrong Direction Heats Everything Nearby

A supply moving air against the containment discharges hot exhaust into the cold aisle. The switch itself may be adequately cooled; what suffers is every device drawing intake air from that aisle, whose inlet temperature rises for reasons that have nothing to do with their own configuration. The fault is in one component and the symptom is distributed across the rack.

Nothing Reports It as Wrong

This is why it persists. The unit is powered and functional, so device health is green. Some platforms warn when airflow directions are mixed inside one chassis, which is a related and also serious mistake, but no device can know which direction the room requires — that is a property of the installation. It is discovered by measuring inlet temperatures, which nobody does until something else fails.

Match the Room, and Keep the Chassis Consistent

The required variant follows the containment design, it is marked on the unit and usually colour-coded, and it must be consistent with the fan trays in the same chassis — opposing directions inside one device produce recirculation and defeat the cooling altogether. ICD confirms the airflow variant before shipping and supplies switching, fan and UCS components for platforms past end of support, tested and covered for one to three years.