某局点规律出现无线丢包严重

普通组网环境

某局点反馈每隔一段时间就会出现无线丢包严重，而且丢包时间持续很短。

无线丢包原因有很多，主要排查思路就两个，一观察丢包时，AP的空口是否异常增高；二观察丢包时，AP的CPU利用率及内存情况。

通过对AP的观察，发现了丢包时AP的cpu会异常升高到90%多，而且转发进程被占满。

  [a2-406-3-probe]dis interface GigabitEthernet 1/0/1 | include Input                                                                                                                       

 Input (total):  19745904 packets, 5893958159 bytes                                                                                                                                       

 Input (normal):  19745904 packets, 5893958159 bytes                                                                                                                                     

 Input:  0 input errors, 0 runts, 0 giants, - throttles                                                                                                                                  

[a2-406-3-probe]dis  cpu                                                                                                                                                                  

Unit CPU usage:                                                                                                                                                                          

      34% in last 5 seconds                                                                                                                                                               

      33% in last 1 minute                                                                                                                                                                

      31% in last 5 minutes                                                                                                                                                               

[a2-406-3-probe]dis interface GigabitEthernet 1/0/1 | include Input                                                                                                                      

 Input (total):  19760223 packets, 5895411001 bytes                                                                                                                                       

 Input (normal):  19760223 packets, 5895411001 bytes                                                                                                                                      

 Input:  0 input errors, 0 runts, 0 giants, - throttles                                                                                                                                  

[a2-406-3-probe]dis  cpu                                                                                                                                                                 

Unit CPU usage:                                                                                                                                                                           

      93% in last 5 seconds                                                                                                                                                               

      33% in last 1 minute                                                                                                                                                               

      31% in last 5 minutes                                                                                                                                                               

[a2-406-3-probe]dis interface GigabitEthernet 1/0/1 | include Input                                                                                                                       

 Input (total):  19768447 packets, 5897240124 bytes                                                                                                                                      

 Input (normal):  19768447 packets, 5897240124 bytes                                                                                                                                      

 Input:  0 input errors, 0 runts, 0 giants, - throttles                                                                                                                                   

[a2-406-3-probe]dis  cpu                                                                                                                                                                 

Unit CPU usage:                                                                                                                                                                          

      93% in last 5 seconds                                                                                                                                                               

      33% in last 1 minute                                                                                                                                                                

      

进行分析后发现异常广播报文均为网关设备发送的ARP报文，通过检查网关设备，发现网关设备上有大量TC报文，导致网关设备不停刷新ARP报文，从而导致无线体验不好。

对网关设备的TC报文来源进行排查，从源头上解决问题。