Most modern applications connect to the web in one way or another, whether to fetch updates, download modules and extensions, verify their integrity, or a combination of all these actions. Those connections also open ports, and in isolated cases conflicts can arise, or worse, that opening is the product of a malicious element that shouldn't be on your system. Today we'll share two methods to check open ports, and by extension, the state of the processes.
If you want to check open ports on your modem/router, all you need to do is visit some online service available (the classic Shields Up! comes to mind, but there are others) and scan a specific port or evaluate an entire range. However, the story doesn't end there: While you read these lines, some process on your computer is connecting to a remote server, opening a port.
In general, there's no reason for paranoia... but if we've learned anything from Windows in recent years, it's that the price of peace is eternal vigilance. If you're interested in checking open ports on Windows, you have two alternatives: use the operating system itself, or download an external tool.
How to check open ports with netstat
- Open the system console with administrator privileges
- Run the command netstat -ab
- Look for processes in the LISTENING state
- Alternatively, use the command netstat -aon
Personally, I find the netstat -aon command much more useful, as it presents a column with the PID that helps us identify the exact process within Task Manager.
Freeware alternative: CurrPorts
If the name sounds familiar, it's because CurrPorts is one of the many free tools developed by the inexhaustible NirSoft. All open TCP and UDP ports on your computer appear immediately in its interface, along with other details such as the name of each process, its full path, exact version, creation date, and more. We can also filter by protocol and TCP/IP version, assign a sound alert when a new port opens, and generate reports in HTML format.
The most important advantages of CurrPorts over the rest are ease of use, portability, not having to fight with the system console, and of course, its freeware profile. Try it!
Download CurrPorts: Click here
