ftp_get: Illegal PORT command - php

Question

On 'localhost' I tried to get a file from FTP server and the local file is successfully created. But when I'm trying in Ubuntu server it's displaying there was a problem and file is not downloading into server. Here is the code. And code file created in this location /var/www/html/
<?php
$local_file = 'whdfcleads.csv';
$server_file = 'hdfc/hdfc_leads.csv';
$ftp_server="*********";
$conn_id = ftp_connect($ftp_server)or die("Couldn't connect to $ftp_server");
$ftp_user_name="*****";
$ftp_user_pass="******";
$login_result = ftp_login($conn_id, $ftp_user_name, $ftp_user_pass);
if (ftp_get($conn_id, $local_file, $server_file, FTP_BINARY)) {
echo "Successfully written to $local_file\n";
}
else{
echo "There was a problem\n";
}
ftp_close($conn_id);
?>
Please help me to solve this issue, in local host it's working fine but in Ubuntu server local file not creating/downloading.
The error is
Array (
[type] => 2
[message] => ftp_get(): Illegal PORT command
[file] => /var/www/html/wftp.php
[line] => 15
)

Answer 1

The "Illegal PORT command" is a message issued by ProFTPD server, when it receives PORT command with an invalid IP address.
What typically happens, when the client is behind a NAT and reports its internal IP address to the server, not knowing the server is not able to reach back to that IP address.
The easiest (and generally correct) solution is to use an FTP passive mode, instead of an active mode (the default in PHP).
In PHP, you switch to the passive mode by calling the ftp_pasv function after the ftp_login:
...
ftp_login($conn_id, $usr, $pwd) or die("Cannot login");
ftp_pasv($conn_id, true) or die("Cannot switch to passive mode");
...
See my article on FTP connection modes to understand, what the active and passive mode means, and why everyone uses the passive mode nowadays.