TCPDump. If you want to capture traffic you need to be using this tool. TCPDump is small lightweight and really easy to understand once you learn the basic syntax. It’s the perfect tool to gather info off the wired or wireless network. If you’re running it on a computer with dsniff installed you can use dsniff to route traffic through your computer and see everything your target is doing even on a switched network (See the article on How-To spy on other users on the local network from back in August )