How to Clear an ARP Cache

By Gil David

ARP (Address Resolution Protocol) is used by devices in a network to map between logical addresses and physical addresses. For example, ARP maps IP addresses of gateways in the Internet to their corresponding MAC addresses, which are the hardware (network card) addresses. To send data in a network, the operating system of the sender machine uses the ARP mapping. Since the process of mapping slows the network, the operating system maintains a database of already known ARP mappings, the ARP cache, which reduces the traffic in the network. When you encounter network connectivity problems, like websites that are not responding or webpages that are not loading, you might have problem with your ARP cache. Clearing the cache can solve this problem.


Step 1

Open the "Command Prompt," the Windows application that enables running Windows commands and software applications, by clicking the Windows "Start" button, clicking "Programs," clicking "Accessories" and then clicking "Command Prompt."

Step 2

Type "netsh interface ip delete arpcache" in the Command Prompt to clear your ARP cache.

Step 3

Type "arp -a" in the Command Prompt to verify that the ARP cache was cleared. The output of this command should be "No ARP Entries Found."