FTP server subcommand
To identify the
port on which the client will listen for a data connection, use the PORT FTP
server subcommand in this format:
- h n
- Represents the system IP address and is a character string that is a decimal
value between 0 and 255.
- p n
- Represents the TCP port number and is a character string that is a decimal
value between 0 and 255.
To convert the p1 and p2 values
to a TCP port number, use this formula:
port = ( p1 * 256 ) + p2
For
example, in this PORT subcommand:
PORT 9,180,128,180,4,8
the
port number is 1032 and the IP address is 9.180.128.180.
Note: After the
server closes the connection, it cannot connect to the same client IP address
and port number until a two-minute time delay has occurred as specified in
TCP/IP RFC 1122. The server can make a connection to the same client IP address
on a different port number without this restriction.