S5300交换机CPU利用率高

设备CPU使用率达到83%以上

Nov 16 2015 13:05:46 O-R-zyzx-1 %%01DEFD/4/CPCAR_DROP_MPU(l)[0]:Rate of packets to cpu exceeded the CPCAR limit on the MPU. (Protocol=telnet, ExceededPacketCount=020590)
Nov 16 2015 12:55:46 O-R-zyzx-1 %%01DEFD/4/CPCAR_DROP_MPU(l)[1]:Rate of packets to cpu exceeded the CPCAR limit on the MPU. (Protocol=telnet, ExceededPacketCount=024469)
Nov 16 2015 12:45:46 O-R-zyzx-1 %%01DEFD/4/CPCAR_DROP_MPU(l)[2]:Rate of packets to cpu exceeded the CPCAR limit on the MPU. (Protocol=telnet, ExceededPacketCount=018110)
Nov 16 2015 12:35:46 O-R-zyzx-1 %%01DEFD/4/CPCAR_DROP_MPU(l)[3]:Rate of packets to cpu exceeded the CPCAR limit on the MPU. (Protocol=telnet, ExceededPacketCount=021901)
Nov 16 2015 12:25:46 O-R-zyzx-1 %%01DEFD/4/CPCAR_DROP_MPU(l)[4]:Rate of packets to cpu exceeded the CPCAR limit on the MPU. (Protocol=telnet, ExceededPacketCount=021453)

telnet协议造成的cpcar超速

查看设备CPU使用率

<O-R-zyzx-1>dis  cpu-usage
CPU Usage Stat. Cycle: 60 (Second)
CPU Usage            : 83% Max: 99%
CPU Usage Stat. Time : 2015-11-16  13:16:16
CPU utilization for five seconds: 78%: one minute: 78%: five minutes: 82%
Max CPU Usage Stat. Time : 2013-07-12 17:53:14.

TaskName             CPU  Runtime(CPU Tick High/Tick Low)  Task Explanation
BOX                   0%         0/  17d888       BOX Output
_TIL                  0%         0/       0       Infinite loop event task
_EXC                  0%         0/       0       Exception Agent Task
VIDL                 17%         0/28bbdb40       DOPRA IDLE

VT0                  43%         0/67d5564f       VT0 Line user's task

发现虚拟终端任务VTO占到了43%,接下来就是查出哪些IP一直在telnet该设备

某用户长时间telnet该设备所致

display tcp status查看telnet用户登陆情况,发现连接23端口的IP只有1个,该用户一直占用着用户界面,输入命令kill user-interface vty 0断开vty 0用户的连接,执行该命令后cpu使用率正常