Open, closed, or filtered—every port tells a story about what's listening, what's blocked, and what's reachable. Here's how to read it from your machine, across a network, and from the outside world.
Every Internet-connected device is being scanned constantly—probed to discover what services are exposed. Understanding TCP, SYN, and UDP scanning techniques reveals your network the way attackers see it.
Every open port runs code that parses untrusted input—and parsing is where vulnerabilities live. Here's how to find what's listening and shut down what you don't need.
Your port number isn't a secret—it's a trivia question any scanner answers in seconds. Here's what actually protects your systems.
Port knocking hides services behind a secret sequence of connection attempts. Critics call it security theater. But attackers can't exploit what they can't reach—and that's not obscurity, it's geometry.
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