@Override
protected FtpServerFactory createServer() throws Exception {
FtpServerFactory server = super.createServer();
ListenerFactory listenerFactory = new ListenerFactory(server.getListener("default"));
DataConnectionConfigurationFactory dccFactory = new DataConnectionConfigurationFactory();
int passivePort = TestUtil.findFreePort(12444);
dccFactory.setPassivePorts(passivePort + "-" + passivePort);
listenerFactory.setDataConnectionConfiguration(dccFactory.createDataConnectionConfiguration());
server.addListener("default", listenerFactory.createListener());
return server;
}