Which command is used to check if a remote host is available?

The command that is used to check if a remote host is available is "ping." This command sends Internet Control Message Protocol (ICMP) echo request packets to the specified IP address or hostname. If the remote host is reachable and operational, it will respond with ICMP echo replies, indicating that the host is up and responding to network requests. The "ping" command is fundamentally used for diagnosing network connectivity issues, and it provides a simple way to test the availability of remote hosts.

By using "ping," users can quickly determine not only if a connection can be established but also assess the round-trip time for packets sent to the target host, which can help in evaluating the quality and responsiveness of the link to that host. This command is widely utilized in network troubleshooting to ascertain the status of a networked device or server.