B24交换机备份配置？

IBM_2498_B24:admin> configdownload
Protocol (scp, ftp, sftp, local) [ftp]: ftp
Server Name or IP Address [host]: 10.77.77.51
User Name [user]: administrator
Path/Filename [<home dir>/config.txt]: config23.txt
Section (all|chassis|switch [all]): all

                     *** CAUTION ***

This command is used to download a backed-up configuration
for a specific switch. If using a file from a different
switch, this file's configuration settings will override
any current switch settings. Downloading a configuration
file, which was uploaded from a different type of switch,
may cause this switch to fail.

A switch reboot is required for the changes to take effect.

configDownload operation may take several minutes
to complete for large files.
Do you want to continue [y/n]: y
Password:
Login/File information incorrect. Could not connect to remote host.
Terminated
IBM_2498_B24:admin>

10.77.77.51是一个在winserver2008上面的FTP，用网页能开。用的是所有用户，就是server的管理用户
在B24上怎么都传输不过去，请各位大师指点