Currently, I am trying to run ftp commands from telnet client. I was successful with
LIST and when tried
PORT vsftp server is throwing
500 Illegal PORT command. I am following the syntax as specified in RFC 959
DATA PORT (PORT)
The argument is a HOST-PORT specification for the data port to be used in data connection. There are defaults for both the user and server data ports, and under normal circumstances this command and its reply are not needed. If this command is used, the argument is the concatenation of a 32-bit internet host address and a 16-bit TCP port address. This address information is broken into 8-bit fields and the value of each field is transmitted as a decimal number (in character string representation). The fields are separated by commas. A port command would be:
where h1 is the high order 8 bits of the internet host address.
I tried to check if it is a problem related to
vsftpd configuration file using
ftp command. It was working fine with passive mode turn off. So why is it throwing error when I run from telnet client ? Below I attach the screenshot of
telnet session, and
nc session where I am trying to listen for data connection.