Final answer:
The tool designed for sending ICMP echo requests to multiple systems and determining their status by repetitive messaging is known as fping. It's a network utility for simultaneously pinging multiple hosts to gauge their responsiveness.
Step-by-step explanation:
The tool that is designed to send ICMP echo requests to multiple systems, and continues sending messages to those systems before giving up and determining that they are down, is known as fping. This tool is different from the regular ping command in that it can target multiple hosts. fping sends out a series of ICMP echo requests and waits for responses, helping network administrators identify which systems are alive and responsive and which are not. Unlike other tools like arp scan, Mega Ping, or Qping, fping is specifically designed for batch processing, making it a useful tool for scanning multiple hosts, often used in larger networks or for monitoring purposes.