FTP Server in passive mode with HAProxy Frontend and Backend nodes

[Roberto Carna]

Dear all, I have to put to work an FTP server (Filezilla) in my backend
network, as this:

Internet -- Firewall -- HAProxy Frontend -- HAProxy Backend -- FTP server
(passive mode)

This is my configuration in my HAProxy FE:

frontend Frontend_FTP

   bind *:21
   bind *:20000-20010
   mode tcp
   option tcplog
   timeout client 1h
   default_backend HAProxy_BE

backend HAProxy_BE

        mode tcp
        server HAProxy-Node-2 172.17.17.1:21 check port 21

This is my configuration in my HAProxy BE:

frontend Backend_FTP

   bind *:21
   bind *:20000-20010
   mode tcp
   option tcplog
   timeout client 1h
   default_backend FTP_Server

backend FTP_Server

        mode tcp
        server HOST-FTP 10.12.1.4:21 check port 21

The FTP control session works OK, but the data session fails.

Is there any error in the HAProxy configuration files from Frontend and
Backend?

Special thanks, regards!!!