Redhat secure server - Apr 2003 - Iptables / FXP / wu-ftpd

Not sure if this falls under this topic.
Just curious what my iptables and wu-ftpd
settings should be to allow FXP to be capable.

Any clues?  I''ve tried looking thru all sorts of help
files, but can''t seem to find a setting that works.

Thanks.

Rob