The Fans in any NetVanta switch may run at 100% for any number of reasons. Temperature is obviously the most common, but other factors can cause the board to be hotter than the room temperature its set at.
The good news is the fans in NetVanta switches are actually designed to run at 100% all of the time. We temper the rate down ourselves in software. So there is no concern that there is anything wrong with the fans, nor that they will imminently stop working for any reason.
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