(enabled by adding LOOKUP_PASV_IP to the "Options" value in the [ftp] section
of your ctrl/sbbs.ini.
This option tells the FTP server to perform a hostname lookup (on the BBS's
hostname) to determine the correct/current public IP address to use in
PASV responses. This is one more kludge to work around stupid NAT devices
(consumer firewalls/routers).