iptables doesn't work with me

Agent007 · 01-22-2004, 09:31 AM

first of all .. im newbie when it comes to networking in all operating systems not just linux .. so please be patient with me
I'm trying to open ftp port on my linux box .. but I can't get it to work .. don't know
when i type: iptables -I INPUT 1 -p tcp --dport 21 -j ACCEPT
it works .. but when i try to upload something or download something (using any account) from another windoze pc .. it refuses my connection
what's wrong ????

codedv · 01-22-2004, 10:45 AM

You may find this useful:
http://www.sns.ias.edu/~jns/security...track.html#FTP

twantrd · 01-22-2004, 05:30 PM

Hi, I think this is what you need:

Quote:

iptables -I INPUT 1 -p tcp --dport 21 -j ACCEPT

iptables -A INPUT -p tcp --dport 21 -j ACCEPT

Try that and see if that helps....

-twantrd

codedv · 01-23-2004, 01:32 AM

Quote:

Originally posted by twantrd
Hi, I think this is what you need:

iptables -A INPUT -p tcp --dport 21 -j ACCEPT

Try that and see if that helps....

-twantrd

The problem with FTP is that it uses more than one port. One port is used as the connection port and one is used as a data channel.

The data channel will vary. If active FTP is being used then the client can choose which port to use. If it is passive FTP then the server chooses. So one rule for FTP will not work.

palmercabel · 01-23-2004, 07:14 AM

Agent007, you may need to control access to FTP through tcp wrappers rather than iptables. It would help to know which FTP server you are running.