reset arp { dynamic [ ip ip-address [ vpn-instance vpn-instance-name ] ] | interface interface-type interface-number[.subinterface-number ] [ ip ip-address ] | static }
| Parameter | Description | Value |
|---|---|---|
| dynamic | Clears dynamic ARP entries | - |
| interface interface-type interface-number | Specifies the interface type and number.
|
- |
| subinterface-number | Specifies the number of a sub-interface. | The value is an integer that ranges from 1 to 4096. |
| ip ip-address | Clears dynamic ARP entries with a specified IP address. |
The value is in dotted decimal notation. |
| vpn-instance vpn-instance-name | Specifies the VPN instance name. | The value must be an existing VPN instance name. |
| static | Static ARP entries cannot be restored after being cleared. Exercise caution when you clear static ARP entries. | - |
Usage Scenario
When an attacked device learns a large number of invalid ARP entries, ARP entries of valid users may fail to be saved and these users may fail to access the network. The reset arp command can be used to delete ARP entries. After that, the device relearns ARP entries to ensure that users can access the network.
To delete ARP entries based on a certain IP address, you can run the reset arp dynamic ip ip-address [ vpn-instance vpn-instance-name ] or reset arp interface interface-type interface-number[.subinterface-number ] ip ip-address command.
Precautions
The reset arp command deletes mappings between IP addresses and MAC addresses. As a result, users may fail to access some network devices and services may be interrupted.
The minimum interval for running the command (only the reset arp command in which ip ip-address is not specified) to clear ARP entries is 20 seconds.