How to check TCP port openness using built-in tools?

The article focuses on the issue of testing port reachability, offering various approaches to this important topic. Author Care Hart points out that we often rely on the telnet tool to verify the availability of ports; however, there are other lesser-known methods that can be just as effective. The article discusses alternatives such as using network tools that can provide more detailed insights into the state of the ports. Additionally, Care Hart presents arguments in favor of more advanced solutions that can identify connectivity issues more effectively. The conclusion of the article reminds readers that understanding various available tools and their applications can significantly enhance our ability to troubleshoot network-related problems.