Free CompTIA Network+ N10-008 Practice Question

Using the telnet command followed by the web server's IP address and the port number that the web server communicates on (commonly port 80 for HTTP or port 443 for HTTPS), is an effective way to verify if the port is open or if it has been blocked by a firewall. This is because Telnet can be used to establish a rudimentary connection to the specified port. If the connection fails, this could indicate a blocked port. Pinging the IP address would only verify if the host is reachable and would not give information about specific port availability. Changing firewall settings without testing is premature and could have negative security implications. Checking your email settings would not address the issue of port accessibility.