Which tool confirms connectivity between hosts?

Ping is the tool specifically designed to confirm connectivity between hosts. It operates by sending Internet Control Message Protocol (ICMP) Echo Request messages to the target host and waiting for an Echo Reply. If the target host is reachable and configured to respond, it will reply to the Ping, indicating that a successful connection has been established.

While Telnet can be used to check connectivity by attempting to establish a session with a specific service on a host, it is more applicable for testing access to specific ports rather than simply confirming the ability to reach a host. Trace, in the context of network tools, is often associated with tracing the route packets take to reach a destination but does not explicitly confirm connectivity. ARP, on the other hand, is used for resolving IP addresses to MAC addresses within a local network, rather than testing connectivity between hosts in a broader sense. Thus, Ping is the most appropriate tool for confirming basic connectivity.