Which command tests a connection to srv.sophos.local on TCP port 8191?

Using the telnet command to test a connection to a specific TCP port, such as 8191 on srv.sophos.local, is an effective method for assessing whether the service on that port is accessible. Telnet attempts to establish a connection to the specified hostname and port number, providing direct feedback on whether the connection was successful or if it failed.

When you use telnet and specify a hostname along with the port number, you essentially initiate a TCP connection to that service. If the service is running and accepting connections on the specified port, telnet will connect and typically provide a blank screen or response, indicating that the communication channel is open.

Other commands have different purposes, making them unsuitable for testing TCP connections to a specific port in the way that telnet does. For example, ping is used to check network connectivity but operates at the ICMP level, without testing specific TCP ports. Netstat is primarily used for viewing active network connections and listening ports on the local machine, not for testing connectivity to a remote host on a specific port. Tracert, on the other hand, is utilized to determine the route packets take to reach a destination and does not test the availability of a specific port.