arp

The arp Command in Windows is a command-line utility used to view and modify the Address Resolution Protocol (ARP) cache. The ARP cache is a table that stores the Media Access Control (MAC) addresses associated with IP addresses of devices on the local network.

Key Uses of the ARP Command:

• Displaying the ARP Cache:

  The arp -a command shows the current ARP table, listing IP addresses and their associated MAC addresses. This can help identify devices on your network. 
• Clearing the ARP Cache:

  The arp -d command deletes all entries in the ARP cache, forcing the system to re-resolve IP addresses. 
• Adding ARP Entries:

  The arp -s command allows you to manually add a static entry to the ARP cache. This is useful for manually mapping IP addresses to MAC addresses, for example, if a device has a static IP and MAC address. 
• Displaying Specific ARP Entries:

  You can use arp /a inetaddr to display the entry for a specific IP address, according to Microsoft. 
• Displaying ARP Entries for a Specific Interface:

  You can use arp /a /n ifaceaddr to display the ARP table for a specific network interface, where ifaceaddr is the IP address of that interface. 

Additional Notes:

• The ARP cache is dynamically updated as your computer communicates on the network. 
• ARP is fundamental to network communication, allowing computers to find each other on a local network. 
• The ARP command can be a helpful tool for troubleshooting network connectivity issues.