FTP+NAT: some ftp clients work, some don't

[shpokas]

Without going into much details right away, perhaps someone has a clue why some ftp clients can connect to vsftpd server behind pfsense and some can't?

CAN
OS X ftp enters extended passive mode and all is good.
ncftp on all platforms

CAN'T
windows builtin ftp disconnects after "quote epsv" command
Centos/RHEL default ftp - returns "failed to establish connection" after "quote epsv" command

pfsense
dual WAN load balanced
client connects to WAN1 IP address
21 port forwarded to ftp server. according to sparse docs on the subject, with 2.x everything else happens automagically.

server
vsftpd on debian with pasv mode enabled and port range specified.
firewall off.

thanks,
shpokas

[johnpoz]

what version of windows..  epsv is extended passive.

I would prob disable that on your server if you don't want clients using it.