arping

Arping is a command-line tool used to send Address Resolution Protocol (ARP) requests over a network to determine if a specific host is online or not. ARP is a protocol used to resolve an IP address to its corresponding MAC address on a local network.

The arping tool operates at the Network Layer (Layer 3) of the OSI model. It is particularly useful in scenarios where traditional ping commands may not work, such as in situations where network devices may block or ignore ICMP (Internet Control Message Protocol) ping requests.

Unlike the regular ping command, which sends ICMP echo requests, arping sends ARP request packets to the specified IP address. If the target IP address is active and reachable, it will respond with an ARP reply packet, indicating its presence. If there is no response, it means the target IP address is not active or not reachable.

Arping can be used for various purposes, including network troubleshooting, discovering available hosts in a network, checking host availability, diagnosing network connectivity issues, and verifying IP-to-MAC address mappings.

The syntax of arping command is generally as follows:

arping [options] destination_ip_address

Some commonly used options with arping include setting the source IP address, specifying the network interface, defining the packet size, setting the timeout value, etc.

Overall, arping provides a simple and effective way to verify the reachability of IP addresses within a network using ARP protocol.