ARP Commands

ARP - Address Resolution Protocol

Display and modify the IP-to-Physical address translation tables used by address resolution protocol.

Syntax

View the current ARP table on the system.
arp -a
arp -g

Add a static ARP entry manually.
arp -s ip_addr eth_addr(MAC_addr)

Delete ARP table entry,
arp -d (To delete complete ARP table)
arp -d ip_addr (To delete entry for a specific IP address)

ARP Help
arp /?

If two hosts on the same sub-net cannot ping each other successfully, try running ARP -a to list the addresses on each computer to see if they have the correct MAC addresses.

A host's MAC address can be checked using IPCONFIG. If another host with a duplicate IP address exists on the network, the ARP cache may have had the MAC address for the other computer placed in it. ARP -d is used to delete an entry that may be incorrect.

Examples

Display the ARP cache tables for all interfaces:

C:\Users\lmntechnohub>arp -a

Interface: 157.25.35.15 --- 0xb
  Internet Address      Physical Address      Type
  157.25.35.4            00-1e-8c-cc-30-77     dynamic
  157.25.35.5            00-1e-8c-69-38-03     dynamic
  157.25.35.7            38-60-77-be-04-38     dynamic
  157.25.35.9            74-d4-35-78-d7-f1     dynamic
  157.25.35.10           70-71-bc-5c-72-fe     dynamic
  157.25.35.11           70-71-bc-5c-72-e0     dynamic
  157.25.35.12           74-d4-35-78-8a-94     dynamic
  157.25.35.16           54-be-f7-0d-05-94     dynamic
  157.25.35.17           54-be-f7-0d-05-88     dynamic
  157.25.35.29           00-e0-1c-3c-30-6a     dynamic
  157.25.35.30           00-25-5e-29-50-b9     dynamic
  157.25.35.255          ff-ff-ff-ff-ff-ff     static
  192.168.1.1           38-60-77-be-04-38     dynamic
  192.168.1.255         ff-ff-ff-ff-ff-ff     static
  224.0.0.252           01-00-5e-00-00-fc     static

Display the ARP cache table for the interface on IP address 10.1.4.99 ( -N <IP_addr> Display the ARP entries for the network interface specified.):

C:\Users\lmntechnohub>arp -a -N 17.65.115.15

Interface: 17.65.115.15 --- 0xb
  Internet Address      Physical Address      Type
  17.65.115.4            00-1e-8c-cc-30-77     dynamic
  17.65.115.5            00-1e-8c-69-38-03     dynamic
  17.65.115.7            38-60-77-be-04-38     dynamic
  17.65.115.9            74-d4-35-78-d7-f1     dynamic
  17.65.115.10           70-71-bc-5c-72-fe     dynamic
  17.65.115.11           70-71-bc-5c-72-e0     dynamic
  17.65.115.12           74-d4-35-78-8a-94     dynamic
  17.65.115.16           54-be-f7-0d-05-94     dynamic
  17.65.115.17           54-be-f7-0d-05-88     dynamic
  17.65.115.29           00-e0-1c-3c-30-6a     dynamic
  17.65.115.30           00-25-5e-29-50-b9     dynamic
  17.65.115.255          ff-ff-ff-ff-ff-ff     static
  192.168.1.1           38-60-77-be-04-38     dynamic
  192.168.1.255         ff-ff-ff-ff-ff-ff     static
  224.0.0.252           01-00-5e-00-00-fc     static


Add a static ARP cache entry on IP addr 10.52.44.74 to the physical address 00-AA-21-4A-2F-9A:

C:\Users\lmntechnohub>arp -s 10.52.44.74 00-AA-21-4A-2F-9A

C:\Users\lmntechnohub>arp -a

Interface: 10.10.10.15 --- 0xb
  Internet Address      Physical Address      Type
  10.52.44.74           00-aa-21-4a-2f-9a     static
  192.168.1.1           38-60-77-be-04-38     dynamic
  192.168.1.255         ff-ff-ff-ff-ff-ff     static
  224.0.0.252           01-00-5e-00-00-fc     static


Enjoy! and stay Connected.