FTP client behind a gateway

FTP client behind a gateway

[Julio Cesar Ody]

Hello. I don't know if anybody else faced this problem, but when I'm 
behind a gateway (using iptables to perform NAT), I can connect to any 
FTP server (using the client machines behind the gate) but when I 
request a directory listing by using the "ls" command, it refuses to 
enter passive mode. The same doesn't happen when I do it with the 
gateway machine. Any solutions or ideas ? Thanks again.


Julio Cesar Ody

Re: FTP client behind a gateway

[Antony Stone]

On Tuesday 29 October 2002 11:51 am, Julio Cesar Ody wrote:

> Hello. I don't know if anybody else faced this problem, but when I'm
> behind a gateway (using iptables to perform NAT), I can connect to any
> FTP server (using the client machines behind the gate) but when I
> request a directory listing by using the "ls" command, it refuses to
> enter passive mode. The same doesn't happen when I do it with the
> gateway machine. Any solutions or ideas ? Thanks again.

I know you're using passive mode and not active, but have you included 
support (either compiled in or as a module) for ftp connection tracking and 
ftp nat ?

NAT still needs to know the port numbers used in passive ftp, so it needs the 
helper module loaded in order to see the PORT command.

Antony.

-- 

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when it's good, it's very very good;
when it's bad, it's still better than nothing.

RE: FTP client behind a gateway

[R. Sterenborg]

> Hello. I don't know if anybody else faced this problem, but when I'm
> behind a gateway (using iptables to perform NAT), I can connect to
any
> FTP server (using the client machines behind the gate) but when I
> request a directory listing by using the "ls" command, it refuses to
> enter passive mode. The same doesn't happen when I do it with the
> gateway machine. Any solutions or ideas ? Thanks again.

If you compiled these as modules ;
do you have the ip_nat_ftp and ip_conntrack_ftp modules loaded (lsmod)
?


Rob