Beefy Boxes and Bandwidth Generously Provided by pair Networks
XP is just a number
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
I've covered this previously for a couple of others experiencing the same problem - When connecting to a FTP server, two socket streams are used for communications - The first is the control connection initiated by your FTP client between which the FTP client and server exchange commands and replies (TCP socket 21). The second is a full-duplex connection over which data is transferred in a specified mode and type. The data transferred may be part of a file, an entire file or a listing of files within a directory. Typically, this data port is the port adjacent to the control port (TCP socket 20). In general, it is the FTP server's responsibility to initiate and maintain the data connection.

According to the output supplied, it appears that the poster of this question is attempting to connect to the FTP from a machine with a private class address - This host address, along with the preferred socket for data communications, are sent to the server via the PORT command. I would suspect that the poster is connecting to the FTP server host through a network firewall or layer of address translation and as such, the data connection from the server to your machine is failing because the FTP server is unable to reach your private machine.

The means by which to fix this is to switch to passive FTP transfer mode via the PASV command - This command changes the default behaviour of data port negotiation, shifting the onus for responsibility for data port establishment and maintenance back to the client. This allows the client to control its only data connection through the network firewall or translation layer, allowing normal FTP communications to occur. eg.

use Net::FTP; # Passive mode can be set with object initiation my $ftp = Net::FTP->new( $hostname, Debug => 1, Passive => 1 ) or die +$!; $ftp->login( $user, $password ); # Or with $object->pasv; $ftp->pasv;

Further information on this topic can be found in RFC documents File Transfer Protocol, Requirements for Internet hosts - communication layers and Firewall-Friendly FTP.

 


In reply to Re: Re: Re: Re: Net::FTP and by rob_au
in thread Net::FTP and 'Illegal PORT command' by Bukowski

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others musing on the Monastery: (5)
As of 2022-08-13 08:32 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?