Firewalls can be tricky if you don't know them

For some reason, I've ran into two cases with different people that firewalls cause them problems with the FTP protocol. Now, firewalls can be tricky, especially if you don't need to configure them, or you don't exactly understand what ports you need to open and in which direction.

Now, speaking of the port issue, I found a great Microsoft Knowledge Base article (ID 832017) which combines a lot of information about which ports Windows operating systems need. For example, can you easily remember the ports you need to open to get file sharing to work? Or MSMQ? It is all in this document. Good luck!