What are the best ways to determine what port an application is using?

Question

This is an adapted version of a question from someone in my office. She's trying to determine how to tell what ports MSDE is running on for an application we have in the field.

Answers to that narrower question would be greatly appreciated. I'm also interested in a broader answer that could be applied to any networked applications.

Answer 1

Download currports from here.

It will show you which ports are open and which processes are associated with each port.

Scroll down to: Download CurrPorts

Answer 2

netstat -b

from the command line will display the application name, process owner, address, and port number used for all running applications.

Answer 3

netstat -b is a great answer, you may need to use the -a option as well.

Without -a netstat shows active connections, with -a it shows listening ports with no active clients as well.

Answer 4

I've always liked the sysinternals app TCPView, which can now be found here. Good luck.