Your company's network has recently experienced unexpected downtimes. After initial troubleshooting, you suspect that there might be an issue with the environmental conditions in the server room where your core networking devices are located. To help prevent future network outages, what is the BEST sensor or statistic to monitor to alert you in case of environmental conditions that could lead to hardware failure?
Keeping a log of CRC errors on switches
Monitoring the bandwidth usage of the core router
Temperature sensors in the server room
Regularly checking the uptime/downtime statistics of the network devices