Procedure

1. Check whether the switch has received too many ICMP packets. Excess ICMP packets are discarded by CAR, but not sent to the CPU. The commands vary according to switch models and software versions. Check whether the Drop counter in the command output increases.
   • For modular switches running V100R002 and fixed switches running V100R005:

2. <HUAWEI> display cpu-defend icmp statistics all 
   CPCAR on mainboard 
   ------------------------------------------------------------------------------- 
   Packet Type         Pass(Bytes)  Drop(Bytes)   Pass(Packets)   Drop(Packets) 
   icmp                0            0               0               0 
   ------------------------------------------------------------------------------- 
   CPCAR on slot 4 
   ------------------------------------------------------------------------------- 
   Packet Type         Pass(Bytes)  Drop(Bytes)   Pass(Packets)   Drop(Packets) 
   icmp                0            0               0               0 
   -------------------------------------------------------------------------------

   • For modular switches running V100R003 or later and fixed switches running V100R005 or later:

3. <HUAWEI> display cpu-defend statistics packet-type icmp all 
   Statistics on mainboard: 
   ------------------------------------------------------------------------------- 
   Packet Type         Pass(Bytes)  Drop(Bytes)   Pass(Packets)   Drop(Packets) 
   ------------------------------------------------------------------------------- 
   icmp                4488           0              44               0 
   ------------------------------------------------------------------------------- 
   Statistics on slot 3: 
   ------------------------------------------------------------------------------- 
   Packet Type         Pass(Bytes)  Drop(Bytes)   Pass(Packets)   Drop(Packets) 
   ------------------------------------------------------------------------------- 
   icmp                0            0               0               0 
   -------------------------------------------------------------------------------

   If the Drop counter increases, increase the CAR value and test whether the problem is solved. Change the CAR value as follows:

   1. Run the cpu-defend policy command to set the CAR value.

      <HUAWEI> system-view 
      [HUAWEI] cpu-defend policy 1 
      [HUAWEI-cpu-defend-policy-1] car packet-type icmp cir 256 
      [HUAWEI-cpu-defend-policy-1] display this 
      # 
      cpu-defend policy 1 
      car packet-type icmp cir 256 cbs 48128 
      #

   2. Apply the policy globally or to a specified LPU.
      • Global:

        [HUAWEI-cpu-defend-policy-1] quit 
        [HUAWEI] cpu-defend-policy 1 global

      • To an LPU:

        [HUAWEI] slot 1 
        [HUAWEI-slot-1] cpu-defend-policy 1 
        [HUAWEI-slot-1] dis this 
        # 
        slot 1 
        cpu-defend-policy 1 
        #

Fonte: http://support.huawei.com/onlinetoolsweb/ptmngsys/Web/tsrev_s/en/content/s/10_edesk_Ping_Fail/edesk_Ping_Fail_edesk008.html