I will give a quick overview of the differences between them and describe some situations where you may choose one over the other. Why do we use TCP by default? TCP is an older technology than UDP and they operate at different levels of the OSI model. That’s it, you have opened a TCP port and established a connection between two systems. You can also use ‘localhost’ in place of the IP, or use the IP of your second PC here if you are making a remote connection. In order to establish a connection, you will use another terminal and enter the following. This command opens port 8080 and tells the machine to begin listening on this port. You can set up a connection using TCP to connect two separate machines, you can also emulate that connection using the terminal. Create a Connection Using TCP with netcat commandĪs I mentioned earlier, the core functionality of netcat is joining two machines together. The syntax can vary depending on the application, but for most uses, your commands will follow this basic pattern. Here’s the syntax for the nc command: nc I will explain how this works, but keep in mind this is no longer part of the nc software due to its potential for malicious use. Notoriously, netcat can be used for creating “back door” access. I will highlight some of the more common applications throughout this article. It can be used for simple file sending, chatting, web serving, running code remotely. Netcat is known as the IT “Swiss Army Knife” because of its wide range of functionalities. Communication can work bidirectionally so files or information can move from listener to client or client to listener. Once established there are many potential use cases. The name is a portmanteau of network and concatenate, which is a fancy word for joining things together.Ĭonnections can be made directly between machines via TCP or UDP ports. The core functionality of Netcat is allowing two computers to connect and share resources. It is simple to use and essential learning for everyone interested in network communication. Netcat is a powerful and versatile network tool that is available for Linux, Mac, and Windows machines.

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