arp rate-limit

Function

The arp rate-limit command configures the rate limit of ARP VLAN CAR for ARP packets on an interface.

The undo arp rate-limit command restores the default configuration.

By default, the rate limit of ARP VLAN CAR for ARP packets configured on an interface is 20pps.

Format

arp rate-limit rate

undo arp rate-limit

Parameters

Parameter	Description	Value
rate	Specifies the rate limit of ARP VLAN CAR for ARP packets configured on an interface. When the threshold is reached, perform the CAR operation for the packets.	The value is an integer, in pps. The value is 0 or an integer ranging from 21 to 1024. If the value is 0, ARP VLAN CAR is not performed for ARP packets to be sent to the CPU.

Parameter

Description

Value

rate

Specifies the rate limit of ARP VLAN CAR for ARP packets configured on an interface. When the threshold is reached, perform the CAR operation for the packets.

The value is an integer, in pps.

The value is 0 or an integer ranging from 21 to 1024. If the value is 0, ARP VLAN CAR is not performed for ARP packets to be sent to the CPU.

Views

100GE interface view, 10G LAN interface view, 10G WAN interface view, 40GE interface view, Eth-Trunk interface view, GE optical interface view, GE electrical interface view, VBDIF interface view, VE sub-interface view, VLANIF interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
hostdefend	write

Usage Guidelines

Usage Scenario

To set the rate limit of ARP VLAN CAR for ARP packets on an interface, run the arp rate-limit command.

If the rate of ARP packets on an interface does not exceed the rate limit of CP-CAR, ARP VLAN CAR is not performed on the interface.
If the rate of ARP packets on an interface exceeds the rate limit of CP-CAR, ARP VLAN CAR is triggered on the interface, and two-level rate limiting is performed for ARP packets to be sent to the CPU.

After ARP VLAN CAR is triggered on an interface, if the rate at which ARP packets are sent to the CPU does not exceed the rate limit of ARP VLAN CAR, CP-CAR is performed for all the ARP packets that are allowed to pass through. If the rate of ARP packets to be sent to the CPU exceeds the rate limit of ARP VLAN CAR, the excess packets are discarded, and CP-CAR is performed for the ARP packets that are allowed to pass through.
CP-CAR is then performed for ARP packets that have experienced ARP VLAN CAR. If the rate of ARP packets to be sent to the CPU does not exceed the rate limit of CP-CAR, all ARP packets are sent to the CPU. If the rate of ARP packets to be sent to the CPU exceeds the rate limit of CP-CAR, the excess ARP packets are discarded, and the ARP packets that are allowed to pass through are sent to the CPU.
If arp rate-limit 0 is specified in the command, ARP VLAN CAR is not performed for ARP packets, and ARP packets are simply restricted using CP-CAR.

Configuration Impact

If you configure a rate limit (1024 pps, for example) which is larger than the default rate limit of CP-CAR, the configured ARP VLAN CAR cannot take effect. CP-CAR can be configured by running the car arp cir cir-value command. For details, see Configuring the CAR. The configuration of CP-CAR can be checked by running the display cpu-defend car arp statistics command.

You can run the display arp rate-limit interface command to check the rate limit of ARP VLAN CAR configured on an interface.

Precautions

After configuring ARP VLAN CAR, the system checks the rate of ARP packets at an interval of 5 seconds. If no packet loss is detected after three continuous checks, ARP VLAN CAR will not take effect.

Example

# Configure ARP packets rate limit on GE 0/1/0 to 50pps.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet 0/1/0
[~HUAWEI-GigabitEthernet0/1/0] arp rate-limit 50

# Configure the rate limit of ARP VLAN CAR on GE 0/1/0 to 0.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet 0/1/0
[~HUAWEI-GigabitEthernet0/1/0] arp rate-limit 0