FTP Outgoing - random port incoming

[Fabiano Pacheco]

Hi All,
�
Does anybody knows why when I try to FTP anywere, loggin on my FW, I saw a packet 
coming from port 20 (remote) to a randon port on my FW....
�
But there is anything very strange occurring.....I can authenticate on FTP 
Server....but when I try to get a list (ls or dir or something else.....) simply the 
server give me a packet on a random port....so my FW blocks!!!
�
Is it right or not? If right, what I have to do on my fw to permit this packet traffic?
�
Thanx,
�
Fabiano Pacheco