weird problem with ipfw and ftp

[Ed Stover]

On Tue, 2005-04-12 at 09:05 +0200, Clement Twine wrote:
> hi freebsd users,
> 
> i have a problem with users accessing my ftp service from the
> internet. everything was working well until i changed from
> Linux/shorewall to freebsd/ipfw as my firewall.
> 
> my setup is briefly as follows:
> 
> FTP_Server (10.0.0.1) --- Firewall (IPFW) ----- INTERNET
> 
> The linux rules were just two (and were working):
> 
> 	allow tcp from any to 10.0.0.1 21
> 	allow tcp from 10.0.0.1 21 to any
> 
> I have the following in ipfw but they have refused to work!
> 
> 	ipfw add 00010 allow tcp from any to 10.0.0.1 21
> 	ipfw add 00011 allow tcp from 10.0.0.1 21 to any
> 
> 
> The problem is that an ftp session is established, but when the
> session enters passive mode, the ftp session hangs. Are there any
> other ports that need to be opened? Has anyone had such a problem
> before? I can see in the logs that unprivileged ports are
> responding from the ftp server to the requestor - but have tried
> all combinations of rules to no avail!
> 
> Please help!
> 
> Regards,
> 
> Clem.
> 
> 
I usually do port forwarding from my natd.cf on my open type firewalls
and it works fine. 
#/etc/natd.cf
log             yes
deny_incoming   no
use_sockets     yes
same_ports      yes
verbose         no
port            8668
interface       xl1
unregistered_only       no
redirect_port          tcp 10.1.1.1:20 20
redirect_port          udp 10.1.1.1:20 20
redirect_port          tcp 10.1.1.1:21 21
redirect_port          udp 10.1.1.1:21 21
#EOF