Hi Rengar,
The default cpu-defend policy cannot be configured.
You can create a cpu-defend policy, modify parameters, and then invoke. For example, to configure CPCAR rate limiting, run the following command:
[Huawei] cpu-defend policy test //Create a policy named test.
[Huawei-cpu-defend-policy-test] car packet-type arp-reply cir 768 cbs 144384
[Huawei-cpu-defend-policy-test] car packet-type arp-miss cir 768 cbs 144384
[Huawei-cpu-defend-policy-test] quit
[Huawei] cpu-defend-policy test global
I hope it helps!