simple hint & tip: when adding the FTP server to your configuration through the virtual server part, you have to DISABLE the enabled FTP setting in the Firewall. The Firewall is preventing the FTP server to be accessed. (Firewall has higher priority than the virtual server).
If you forget to disable the firewall setting than the FTP virtual server setting is only working when removing / adding the rule and not save/restart the setting.
More hints tips? ask ;-) I am busy with the SNMP hints & tips tricks for MRTG
After days thinking on what was going wrong with my FTP after changing my router, I googled for “Conceptronic C54APRA2+ ftp server” and, luckily, this was the first result.
Thank you for sharing your hints and tips… and refreshing dumb minds like mine.