Address Resolution Protocol & Display ARP Cache On Computer
Address Resolution Protocol(ARP) finds Physical address(MAC Address) of a network host from IP address of that host. To communicate between two devices, the source device must know the IP address and MAC address of the destination device. If the destination device does not have MAC address of the destination device, it sends ARP broadcast to find the MAC address of the network host belongs to the IP address. The device having the IP address(destination device) will respond to the source device with its MAC address. Source device will update ARP cache with the newly find MAC address of the destination device. ARP cache stores MAC address of the other network devices for the future use and periodically undergo flushing to avoid obsolete entries.
To view the MAC address entries stored in ARP(Address Resolution Protocol) cache on your computer, follow the steps below.
On the table, you can find the Physical address of destination devices with IP addresses. Dynamic APR entries are address automatically but the static types are added manually. Static ARP entries remain on ARP cache on your computer until you reboot the system.
How to Add a Static Entry in ARP Cache
To add a static entry in ARP cache you can use the command arp -s. The format is provided below.
How to Display ARP cache On A Computer
To view the MAC address entries stored in ARP(Address Resolution Protocol) cache on your computer, follow the steps below.
- Start Command Prompt
- Type arp -a to display current ARP entries on your computer
PS: arp -g can also be used to display ARP cache on a computer.
On the table, you can find the Physical address of destination devices with IP addresses. Dynamic APR entries are address automatically but the static types are added manually. Static ARP entries remain on ARP cache on your computer until you reboot the system.
ARP Commands
- arp -v -This APR command shows current ARP entries in verbose mode.
- arp -d - This ARP command can be used to delete a particular ARP entry specified by IP address from ARP cache
- arp -s can be used to add a host to APR cache with MAC address and IP address. ARP entries added to ARP cache using this command is permanent and remains until you reboot your computer.
Other Popular Network Protocols
- Interior Gateway Routing Protocol (IGRP)
- Routing Information Protocol (RIP)
- Internet Control Message Protocol (ICMP)
- Dynamic Host Configuration Protocol (DHCP)
How to Add a Static Entry in ARP Cache
To add a static entry in ARP cache you can use the command arp -s. The format is provided below.
arp -s 224.0.0.22 01-00-5e-00-00-16