FTP and Firewall

With no anonymous access, what ports other than 20-21 must be open for FTP service?

I think I’ve got all the authentication ones open – 113, 88, 106, 3659 – but the FTP service fails whenever I turn on the firewall.

It seems to do the authentication properly then times out on listing the directory of the user access point. With firewall off, the listing is immediate.

I’m probably overlooking something obvious.