What Is My IP

Your public IP is the address the rest of the internet uses to talk to you. Here's what it reveals, what it doesn't, and how to check it.

A quick-reference for IPv4 subnet math — how to read a CIDR, what the mask actually means, and the easy way to count usable hosts.

An 'open port' isn't a vulnerability by itself — it's information. Here's how to tell whether a port being open is fine, suspicious, or actively dangerous, and what to do about each case.