display arp

Function

The display arp command displays Address Resolution Protocol (ARP) entries on a device.

Format

display arp [ network ip-address [ mask | mask-length ] ] [ dynamic | static ]

Parameters

Parameter	Description	Value
network ip-address	Displays ARP entries that contain a specified IP address.	This value is in dotted decimal notation.
mask	Specifies a subnet mask.	This value is in dotted decimal notation.
mask-length	Specifies the length of a subnet mask.	The value is an integer ranging from 1 to 32.
dynamic	Displays dynamic ARP entries.	-
static	Displays static ARP entries.	-

Views

All views

Default Level

1: Monitoring level

Usage Guidelines

To view specific ARP entries on a device, run the display arp command with specified parameters. The command output helps rapidly diagnose an ARP fault.

To view all ARP entries on a device, run the display arp [ dynamic | static ] command.
To view ARP entries with a specified IP address, run the display arp network ip-address [ dynamic | static ] command.
To view ARP entries with IP addresses in specified network segment, run the display arp network ip-address { mask | mask-length } [ dynamic | static ] command.

Example

# Display all dynamic ARP entries on a device.

<sysname> display arp dynamic

IP ADDRESS      MAC ADDRESS     EXPIRE(M) TYPE        INTERFACE   VPN-INSTANCE
                                          VLAN/CEVLAN
------------------------------------------------------------------------------
10.137.230.120  xxxx-xxxx-xxxx            I -         GE0/0/1
192.168.10.2    yyyy-yyyy-yyyy            I -         GE0/0/2
1.1.1.2         zzzz-zzzz-zzzz            I -         GE0/0/3
------------------------------------------------------------------------------
Total:3         Dynamic:0       Static:0     Interface:3

**Table 1** Description of the **display arp** command output
Item	Description
IP ADDRESS	IP addresses in ARP entries.
MAC ADDRESS	MAC addresses in ARP entries. If the field is Incomplete, the entry is a fake ARP entry. If a large number of ARP Miss messages are sent to the upper-layer software, the system resources will be exhausted in processing the ARP Miss messages. To resolve this problem, the system automatically generates ARP fake entries instead of ARP entries.
EXPIRE(M)	Lifetime of ARP entries, in minutes NOTE: When the aging time is 0, the router sends an ARP probe packet to update ARP entries. The deletion time of an ARP entry is determined by the aging detection times and the number of ARP entries to be deleted. The aging detection times can be set using the arp detect-times command.
TYPE	Entry type and number of the slot that obtains the entry. The entry type contains 3 bits. The first bit can be as follows: I: Interface, indicating the MAC address of the interface D: Dynamic, indicating the dynamic entry obtained through the ARP packet S: Static, indicating the static entry obtained through static configuration The second bit can only be F, indicating that the entry is reported to the routing module, the route to this IP address is calculated, and the entries in the FIB are correspondingly updated. NOTE: 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. The third bit indicates the number of the slot that obtains this entry. NOTE: For the ARP entry with the type as "I" or "S", this field displays "-".
VPN-INSTANCE	Name of the VPN instance to which the ARP entry belongs.
INTERFACE	Type and number of the interface that has learnt ARP entries. If the field is Multi-port:n, the interface learns an ARP entry in which the MAC address is configured for n interfaces.
VLAN/CEVLAN	VLAN ID to which the ARP entry belongs.
PVC	Interface where the PVC exists and the corresponding VPI/VCI.
Total	Total number of ARP entries.
Dynamic	Number of dynamic ARP entries.
Static	Number of static ARP entries.
Interface	Number of ARP entries on the interface.