The switch works abnormally for a period time. One time it lasts about 3 hours and the other time it lasts about 1 hour. During this period, the computers can’t ping each other. After this period time, the switch get right auto without any manual action. The logging buffer shows nothing about this err. But “show support” notes “System temperature has exceeded the Upper Threshold limit.” and “System temperature has come down below the upper threshold limit”. Is this error resulted from the high temperature ? and this A4 has about 30 static routers. Do so many static routers lead to the switch work high loading and high temperature ?