What is ARP and How Is It Used?

ARP stands for "Address Resolution Protocol" and is a protocol that used to identify the hardware address of a network host. This type of protocol is used for local area networking (LAN) and for creating pathways for network traffic when the location for the next router must be identified. The method of using Address Resolution Protocol is integrated with numerous different kinds of networks including Internet, Ethernet, Wide Area Networks (WAN), IP (Internet Protocol) and Local Area Networks (LAN).

How ARP Works

Address Resolution Protocol (ARP) operates at Layer 2 in the OSI model which is the protocol that determines and defines the layers of a network. The OSI model is based on the seven layers that make up a network configuration. The Address Resolution Protocol is responsible for converting an IP (Internet Protocol) address of a computer that is connected to the network to a parallel network address.

Address Resolution Protocols reside in the OSI model and are part of the device drivers in network operating systems. ARP works through a network adapter that contains a physical address in the hardware which is known as a MAC (Media Access Control). The address that is in the hardware is a unique address and unlike no other so it can be identified for message delivery. When data is transmitted over the network, the MAC address of the recipient is identified to complete the delivery process.

This is known as an IP-to MAC address mapping. The mapping originated from the ARP cache that is contained in every computer on the network. Over time the ARP cache grows to be quite large and should be cleared to maintain proper function of the Windows operating system.

How to Clear the ARP Cache

It is important to remember to clear the ARP cache on your computer to maintain proper connection with the Internet and the Windows operating system.

To clear the ARP cache click on the "Start" button on your main toolbar and then choose "Control Panel" from the menu. When the window appears, click on "Administrative Tools" and then choose "Computer Management." Click on "Services and Applications" and then double click on "Choose Services." Select "Routing and Remoting Services" and then choose "Look at Startup Type." Click on "Disabled" to view the Service Status and then click "Stop" if it is still working. Click "OK" to begin clearing the ARP cache by using the "netsh" command.

It is important to note that there should not be any other applications running or processes taking place while you are clearing the ARP cache. Running other applications during this process can cause damage to other components in your PC's operating system.