[Problem Description]
The request timeout happens sometimes when pinging the directly connected switch, but the service is normal.
![]()
[Problem Analysis]
1. Checked the physical cable and the rx power of the interface, both of them are normal.
a) Replacing the fiber cable to check if the cable is normal is the most convenient way.
b) To check the rx power, the command display transceiver is needed.
2. Check the CPCAR statistics. Check whether the ICMP packets are discarded because their rate exceeds the CPCAR value.

[Root Cause]
The ICMP packets are dropped by the device because it exceeds the CPCAR limit and this causes the ping request timeout.
[Solution Description]
1. Configure cpu-defend policy:
[HUAWEI]cpu-defend policy huawei
[HUAWEI-cpu-defend-policy-huawei]car packet-type icmp cir xx
[HUAWEI-cpu-defend-policy-huawei]car packet-type arp-miss cir yy
[HUAWEI-cpu-defend-policy-huawei]quit
2. Apply this policy:
[HUAWEI]cpu-defend-policy huawei global
Improper CPCAR settings will affect the services on your network. It is recommended that you contact Huawei engineers before adjusting the CPCAR settings.


