fping

fping is a ping-like program that uses the Internet Control Message Protocol (ICMP) echo request to check if target hosts are responding. Unlike standard ping, which sends packets to one target until it times out or replies, fping supports specifying any number of targets on the command line or reading them from a file. It sends a ping packet to each target and moves to the next in a round-robin fashion for efficient scanning of multiple hosts.

Use cases include network discovery, host availability testing, and monitoring multiple devices simultaneously. It is particularly useful in scripting and automation for checking ranges of IP addresses or lists of hosts quickly. The tool provides various output options to filter alive hosts, show addresses or names, and control verbosity.

fping6 provides backwards compatibility with fping versions below 4.0, supporting similar functionality for IPv6 targets.

fping operates by sending ICMP ECHO_REQUEST packets to specified network hosts. It processes targets in a round-robin manner, sending one ping packet per target before cycling back, rather than waiting for responses from a single host. This enables concurrent probing of multiple hosts with configurable intervals, data sizes, backoff factors, and counts. Reverse DNS lookups can be forced, and outputs can include timestamps, elapsed times, or filtered results for alive targets.