If you've followed security news over the past few days, you've probably seen a lot of hoopla about a TCP split-handshake vulnerability that can affect firewalls and other networking and security devices. Many of the Media's articles characterize this complicated TCP connection attack as, "a hacker…

This article continues our attempt to explain the complex subject of subnetting in terms you can understand even if you're not a rocket scientist.

This Security Fundamentals article explains what IPv4 subnets are, what a subnet mask is, and how you might use them within your own network.

A port is a made-up, or logical, endpoint for a connection, and ports allow the Internet to handle multiple applications over the same wires. Your system figures out how to treat data coming at it partially by looking at what port the data is destined for.

An IP is a numeric identifier that represents a computer or device on a network. Your computer's IP is like your home's mailing address.

Here's how IP routing works, and some suggestions for gaining deeper understanding of IP.