hello, I am getting a TLS issue when there is a firewall between my ftp client (filezilla) and the ftp apache server. without the firewall I am prompted if I want to accept or not the certificate provided by default in the distribution. with the firewall in the middle I get a "500 AUTH not understood" response when command "AUTH TLS" is issued.
do I need to open a special port for the TLS negotiation? thank you.
