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

netstat -b

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

Answer 2

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