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display arp status

Function

The display arp status command displays the delivery status of ARP entries on a device.

Format

display arp status ip-address [ vpn-instance vpn-instance-name ] slot slot-id

Parameters

Parameter Description Value
ip-address Specifies an IP address. The value is in dotted decimal notation.
vpn-instance vpn-instance-name Specifies the name of a VPN instance.

The value must be an existing VPN instance name.

slot slot-id Specifies a slot ID. Set the value according to the device configuration.

Views

All views

Default Level

1: Monitoring level

Usage Guidelines

You can run the display arp status command to check the delivery status of ARP entries with a specified IP address on a device.

Example

# Display the delivery status of ARP entries on card 0.
<HUAWEI> display arp status 10.137.216.1 slot 0
TYPE : D - Dynamic, I - Interface, S - Static                                                                                       
IP ADDRESS      MAC ADDRESS     EXPIRE(M) TYPE        INTERFACE   VPN-INSTANCE                                                      
                                          VLAN/CEVLAN                    STATE                                                             
------------------------------------------------------------------------------                                                      
10.137.216.1    0000-5e00-0149  20        D-0         GE0/0/1                                                                      
                                          4094/-                    Available                                                         
------------------------------------------------------------------------------
Table 1 Description of the display arp status command output

Item

Description

IP ADDRESS

IP address in the ARP entry.

MAC ADDRESS

MAC address in the ARP entry.

NOTE:
If the value of MAC ADDRESS is Incomplete, the current ARP entry is a temporary one. When IP packets trigger ARP Miss messages, the device generates temporary ARP entries and sends ARP Request packets to the destination network segment.
  • When a temporary ARP entry is not aged out, before receiving an ARP Reply packet, the device discards the IP packets matching the temporary ARP entry, and no ARP Miss message is triggered.
  • When a temporary ARP entry is not aged out, after receiving the ARP Reply packet, the device generates a correct ARP entry to replace the temporary entry.
  • After the temporary ARP entry is aged out, the device deletes this entry.

You can run the arp-fake expire-time command to adjust the aging time of the temporary ARP entry.

EXPIRE(M)

Remaining lifetime of the ARP entry, in minutes.

If the remaining lifetime is 0, ARP entry aging probe is to be started. The ARP entry aging time depends on the number of configured aging probe attempts and the number of ARP entries that need to be aged.

TYPE

Entry type and ID of the slot that obtains the entry. The entry type contains 3 bits. The first bit can be any of the following:
  • I: Interface, indicating the MAC address of the interface

  • D: Dynamic, indicating a dynamic ARP entry

  • S: Static, indicating a static ARP entry

The second bit can only be F, indicating that the ARP entry has been reported to the routing module, the route to this IP address has been calculated, and the entry in the FIB table has been updated. If the entry is not reported to the routing module, this field displays -. For the ARP entry with the type as I, this flag bit does not exist.

NOTE:

VLANIF interface and sub-interfaces for VLAN tag termination (including QinQ termination sub-interfaces and Dolt1q termination sub-interfaces) on devices report learned ARP entries to the routing module to generate 32-bit host routes (routes destined for complete host addresses). The host routes are accurate and can be used for packet forwarding. Because the forwarding model of the two types of interfaces requires accurate forwarding paths. However, the outbound interfaces of VLANIF interface routes are VLANIF interfaces. VLANIF interfaces are virtual interfaces that may correspond to multiple physical interfaces, and as a result, such routes cannot be used for packet forwarding. Therefore, the VLANIF interfaces report learned ARP entries to the routing module to generate host routes. As for sub-interfaces for VLAN tag termination, they may correspond to multiple VLANs, and the forwarding model requires that packets be sent to a specified VLAN. Therefore, the sub-interfaces for VLAN tag termination also report learned ARP entries to the routing module to generate host routes.

The third bit indicates the ID of the slot that obtains the entry. For the ARP entry with the type as I or S, this field displays -.

INTERFACE

Type and number of the interface that has learned ARP entries.

VPN-INSTANCE

Name of the VPN instance to which the ARP entry belongs.

To configure the VPN instance name, run the ip vpn-instance command.

VLAN/CEVLAN

ID of the VLAN/CEVLAN to which the ARP entry belongs.

NOTE:

Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support the CEVLAN parameter.

STATE

Whether the ARP entry has been delivered to the chip.

  • Available: The ARP entry has been delivered to the chip.

  • Unavailable: The ARP entry has not been delivered to the chip.

Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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