title: LFTP active mode with servers that do not recognize the PORT command
body: <p>I am using LFTP to transfer files from a server, which unfortunately does not recognize the PORT command. I do not have control over the server (do not know in detail what server is) and I have to use the active mode.</p>
  
  <p>This is the command line as:</p>
  
  <pre><code>lftp -e 'debug 10;set ftp:passive-mode off; set ftp:auto-passive-mode no; ls; bye;' -u user,password ftp://ftp.site.com
  </code></pre>
  
  <p>This is the debug output:</p>
  
  <pre><code>&lt;--- 200 Using default language en_US
  ---&gt; OPTS UTF8 ON
  &lt;--- 200 UTF8 set to on           
  ---&gt; OPTS MLST modify;perm;size;type;UNIX.group;UNIX.mode;UNIX.owner;
  &lt;--- 200 OPTS MLST modify;perm;size;type;UNIX.group;UNIX.mode;UNIX.owner;
  ---&gt; USER xxxxx
  &lt;--- 331 Password required for xxxxx
  ---&gt; PASS xxxxxx
  &lt;--- 230 User xxxxx logged in     
  ---&gt; PBSZ 0
  &lt;--- 200 PBSZ 0 successful               
  ---&gt; PROT P
  &lt;--- 200 Protection set to Private       
  ---&gt; PORT 172,16,133,11,146,168
  &lt;--- 500 Illegal PORT command                    
  ---&gt; LIST
  ---&gt; ABOR
  ---- Closing aborted data socket
  ---- Chiusura del socket di controllo
  </code></pre>
  
  <p>It seems that LFTP renounces to connect to data socket because the remote server does not support the PORT command. Is there a way to convince LFTP can still connect to port 20? By FTP manual obviously no problem.</p>