Showing ARP table information

Show ARP information to view the configuration information in the ARP table.

About this task

When you use the interface parameter with the show ip arp command you can display ARP configuration information only for a specific switch.

The show ip arp command displays all of the configured and dynamically learned ARP entries in the ARP table.

Procedure

  1. Enter Privileged EXEC mode:

    enable

  2. Display the ARP table:

    show ip arp [<A.B.C.D>] [-s <A.B.C.D>] [gigabitEthernet <slot/port[/sub-port]>] [interface <gigabitethernet|vlan>] [nlb] [spbm-tunnel-as-mac][vlan <1-4059>] [vrf WORD<1-16>] [vrfids WORD<0-512>]

Example

Switch:1#show ip arp 
=========================================================================================
                                  IP Arp - GlobalRouter
=========================================================================================
IP_ADDRESS      MAC_ADDRESS        VLAN  PORT                 TYPE    TTL(10 Sec) TUNNEL
-----------------------------------------------------------------------------------------
192.0.2.1    00:09:0f:09:00:08  20    1/3                  DYNAMIC 2159                                                                                              
192.0.2.12   b4:a9:5a:ff:f8:40  20    1/3                  DYNAMIC 458                                                                                               
192.0.2.25   e4:5d:52:3c:65:00  20    -                    LOCAL   2160                                                                                              
192.0.2.154  d4:ea:0e:c2:08:00  20    1/3                  DYNAMIC 2131                                                                                              
192.0.2.157  00:1c:17:b1:ec:80  20    1/3                  DYNAMIC 2131                                                                                              
192.0.2.161  fc:a8:41:fb:40:00  20    1/3                  DYNAMIC 2131                                                                                              
192.0.2.253  e0:db:55:d4:e5:7c  20    1/3                  DYNAMIC 2041                                                                                              
192.0.2.255  ff:ff:ff:ff:ff:ff  20    -                    LOCAL   2160                                                                                              

===========================================================================================
                           IP Arp Extn - GlobalRouter
===========================================================================================
MULTICAST-MAC-FLOODING    AGING(Minutes)       ARP-THRESHOLD
-------------------------------------------------------------------------------------------
disable                   360                  500

c: customer vid   u: untagged-traffic


8 out of 8 ARP entries displayed


ARPs on TX-NNI: Current = 0, re-ARP count = 0

Variable definitions

Use the data in the following table to help you use the show ip arp command.

Variable

Value

-s

Specifies the subnet for the table.

gigabitEthernet

Displays the entries for a particular brouter port.

interface

Displays ARP interface configuration information.

Use the following parameters to display ARP table information specifically for:

  • gigabitethernet {slot/port[–slot/port][,...]} displays IP ARP gigabitethernet interface information

  • VLAN <1-4059> displays IP ARP VLAN interface information

Example: show ip arp interface vlan 1

nlb

Displays the Network Load Balancing (NLB) ARP entries on the switch.

spbm-tunnel-as-mac

Displays the remote host name in the TUNNEL column for the SPBM ARP entry.

vlan

Specifies the VLAN ID in the range of 1 to 4059. By default, VLAN IDs 1 to 4059 are configurable and the system reserves VLAN IDs 4060 to 4094 for internal use. On switches that support the vrf-scaling and spbm-config-mode boot configuration flags, if you enable these flags, the system also reserves VLAN IDs 3500 to 3998. VLAN ID 1 is the default VLAN and you cannot create or delete VLAN ID 1.

Use these parameters to display ARP table information specifically for:

  • vrf WORD<1–16>—the VLAN VRF name in a range from 1 to 16 characters

  • vrfids WORD<0–512>—the VLAN VRF ID in a range from 0 to 512

Example: show ip arp vlan 1 vrf 1

vrf WORD <1-16>

Specifies the name of the VRF.

The total number of ARPs listed in the summary line of the "show ip arp" display represents the total number of ARPs on the chassis including all VRFs.

vrfids WORD <0-512>

Specifies the VRF ID.

The total number of ARPs listed in the summary line of the "show ip arp" display represents the total number of ARPs on the chassis including all VRFs.

<A.B.C.D>

Specifies the network IP address for the table.

Use the data in the following table to help you understand the output of the show ip arp command.

Parameter

Description

IP_ADDRESS

Indicates the IP address where ARP is configured.

MAC_ADDRESS

Indicates the MAC address where ARP is configured.

VLAN

Indicates the VLAN address where ARP is configured.

PORT

Indicates the port where ARP is configured.

TYPE

Indicates the type of learning (dynamic or local) where ARP is configured.

TTL<10 secs>

Indicates the time to live as tenths of a second where ARP is configured.

TUNNEL

Displays the remote host name in the TUNNEL column for the SPBM ARP entry.

MULTICAST-MAC-FLOODING

Displays whether IP ARP multicast MAC flooding is enabled or disabled. When enabled, the ARP entries for multicast MAC addresses are associated with the VLAN or port interface on which they were learned.

AGING (Minutes)

Displays when the ARP aging timer expires.

ARP-THRESHOLD

Displays the maximum number of outstanding ARP requests that a device can generate.
9037147-00 Rev AB