公司一个楼层交换机Cisco2960的F0/21端口自己down了,一片怨声载道,人生鼎沸,妈了个B的。通过命令:shintf0/21看到如下结果:Cisco12#shintf0/21FastEthernet0/21isdown,lineprotocolisdown(err-disabled)HardwareisFastEthernet,addressis0024.1351.2e95(bia0024.1351.2e95)MTU1500bytes,BW100000Kbit,DLY100usec,reliability255/255,txload1/255,rxload1/255EncapsulationARPA,loopbacknotsetKeepaliveset(10se...