lftp问题求教

[sybase2008]

用lftp下载文件，有的文件下了一部分就下不了了，可是用globalspace却可以下载。

在lftp下，断点续传就显示：
---- 正在连接到 172.25.18.200 (172.25.18.200) 端口 21
<--- 220-*
<--- <--- 220-
<--- <--- 220-
<--- <--- 220-
<--- <--- 220-*
<--- 220
<--- 230 Login successful. Have fun.
<--- 250 Directory successfully changed.
**** 超时 - 重新连接
---- 正在连接到 172.25.18.200 (172.25.18.200) 端口 21
<--- 421 There are too many connected users, please try later.
---- 正在连接到 172.25.18.200 (172.25.18.200) 端口 21
<--- 421 There are too many connections from your internet address.
---- 正在连接到 172.25.18.200 (172.25.18.200) 端口 21
<--- 421 There are too many connections from your internet address.
---- 正在连接到 172.25.18.200 (172.25.18.200) 端口 21
<--- 421 There are too many connections from your internet address.
`1.rmvb' at 73523776 (45%) [重新连接前延时: 59]


<--- 220-*
<--- <--- 220-
<--- <--- 220-
<--- <--- 220-
<--- <--- 220-*
<--- 220
<--- 530 Please login with USER and PASS.
<--- 230 Login successful. Have fun.
<--- 500 Unknown command.
`1.rmvb' at 73523776 (45%) [正接收数据]

然后就不动了，请问这是怎么回事？是我lftp设置的问题吗？