This article describes-

1. How to transfer file from/to router when SSH and SFTP is not working?  
2. How to FTP to the router and transfer files?

Despite having ssh services on, if we are unable to sftp to the router, then we can use this option to transfer files to the router.

Step-1: From the server file location perform FTP

lenkas@jtac:~$ ftp
ftp> open AA.BB.CC.DD     <<<<<router IP
Connected to AA.BB.CC.DD 
220 (vsFTPd 3.0.5)

Step-2: Give the router username and password

Name (10.XX.XX.XX:username): root      <<<<< give username as required
331 Please specify the password.
Password:            <<<<< give password as required
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.

Step-3: Use the get and put commands to download and upload files 

ftp> put ptx-fixed.iso                  <<<<<<<<<< transfer command
local: ptx-fixed.iso remote: ptx-fixed.iso
200 PORT command successful. Consider using PASV.
150 Ok to send data.