


Tasklist.exe allows you to find the application using the open port from the command prompt By using Windows Task Manager (CTRL + SHIFT + ESC), we can see that PID 156 belongs to the application called Dropbox.exe.

For example, the image above shows PID 156 being associated with port 17500. The PID information can be used to find which application is using the open port. Using Task Manager to find which application is using the open port This column shows the application process ID (PID) associated with each open port. The column of interest in this case would be the second column.īy using the ‘o’ parameter as part of the netstat command, a fifth column will be displayed as part of the results. The results will be displayed across four columns – the protocol type, local IP address and associated port number, foreign IP address, and state – as shown in the image below. To view which ports are listening (open) on a local host using netstat, from the command prompt type the following:

Netstat.exe, located in the Windows ‘System32’ folder, allows you to view ports that are open or in use on a particular host, but should not be confused with a network port scanner which actually probes a host for open ports. The first tool of note is one many admin and support folk might have heard of the Windows command line utility called netstat.exe. Read Scanning Open Ports in Windows: A Quick Guide (part 2) here and Scanning Open Ports in Windows: Part 3 (NMAP) here. Also, don’t forget to check out the other two posts about scanning open ports in Windows which are a continuation of this post and use different solutions. You might just be surprised at how effective these free utilities are at helping you to scan open ports and get to the root of the problem. In this article we’ll take a quick look at how to view open ports using a number of lightweight freeware tools for Microsoft Windows. When troubleshooting client or server side application network connectivity issues, it is often necessary to determine if access to a certain port that the application uses is being blocked. This post has been reviewed and the information is still relevant as of June 2018.
