开启debugging 模式
>debug transfer all enable
>config paging disable
>transfer download mode sftp
>transfer download datatype code
>transfer download serverip 172.20.1.1
>transfer download filename AIR-CT5520-K9-8-5-160-0.aes
>transfer download path /
>transfer download username conor_wu
>transfer download password 'password to log onto sftp server'
>transfer download start