[Zope] Zope FTP Hang File List Problem

[Marcus Schopen]

hpinson@indepthl.com wrote:
> 
> Hi Dieter.  Yes, we have tried both passive and non passive FTP.  In either
> case, according to the Z2.log we get enter Zope successfully, but the
> session appears to hang on the FTP "LIST" command.  No files or
> directories are visible.
> 
> Several folks have pointed to NAT problems, but why this problem would
> only show up only at the "LIST" request does not make sense to me.

because "LIST" is handeld by FTP data connection. passive FTP goes like this:

1) FTP-Client Port >= 1024 ==== contol connection;SYN     ====> FTP-Server Port 21
2) FTP-Client Port >= 1024 <=== contol connection         ===== FTP-Server Port 21
3) FTP-Client Port >= 1024 ==== contol connection PASV    ====> FTP-Server Port 21
4) FTP-Client Port >= 1024 <=== contol connection OK 4546 ===== FTP-Server Port 21
5) FTP-Client Port >= 1024 ==== data connection SYN       ====> FTP-Server Port 4546
6) FTP-Client Port >= 1024 <=== data connecton            ===== FTP-Server Port 4546

I would check my NAT rules (high ports >= 1024). There must be something wrong with data connection
on high ports.

Hope you'll find it.

Bye
Marcus