PassivePorts [ PassivePorts min-pasv-port max-pasv-port]
server config, <VirtualHost>, <Global>
1.2.0rc2 and later
PassivePorts restricts the range of ports from which the server will select when sent the PASV command from a client. The server will randomly choose a number from within the specified range until an open port is found. Should no open ports be found within the given range, the server will default to a normal kernel-assigned port, and a message logged.
The port range selected must be in the non-privileged range (eg. greater than or equal to 1024); it is STRONGLY RECOMMENDED that the chosen range be large enough to handle many simultaneous passive connections (for example, 49152-65534, the IANA-registered ephemeral port range).