The arp detect-times command sets the number of aging probes for dynamic ARP entries.
The undo arp detect-times command restores the default number of aging probes for dynamic ARP entries.
The default number of aging probes for dynamic ARP entries is 3.
| Parameter | Description | Value |
|---|---|---|
detect-times |
Specifies the number of aging probes for dynamic ARP entries. |
The value is an integer that ranges from 0 to 10. The default value is 3. |
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Usage Scenario
In case that the mapping relationship between the IP address and the MAC address of the peer device exists in the ARP table of the local device, the local device will directly send data packets rather than ARP request packets to the peer device because the MAC address of the peer device exists in the ARP entry of the local device. If the peer device fails to work but the local device is not informed of the fault or change, the local device will send data packets to its original destination MAC address. This causes the traffic to be interrupted.
Therefore, to enhance the communication reliability, run the arp detect-times command to set the aging probe times of a dynamic ARP entry to update the dynamic ARP entry.
After the aging time of a dynamic ARP entry on an interface expires, the switch sends an aging probe packet (ARP Request packet) from the interface. If the switch receives an ARP Reply packet, it updates this dynamic ARP entry and the aging probe ends. If the switch does not receive an ARP Reply packet after the configured aging probe attempts, it deletes the dynamic ARP entry and the aging probe ends.
Precautions
If the number of aging probes is set to 0, the device directly deletes expired dynamic ARP entries.
The arp detect-times command can be configured globally or on the specified interface. If the command is not configured on the interface, the aging detection times of a dynamic ARP entry will be the one configured globally. If the command is both configured globally and on the specified interface, the aging detection times of a dynamic ARP entry will be the one configured on the interface.