Hello, this is my first message so I hope I'm doing this right ! :)
I've got iptables setup and running well on my server and up to now I've
not had any problems, however I have just installed a backup system
which needs to connect by FTP to a distant server.
With my firewall disactivated all works fine, however with the firewall
activated when I use the "ls" command of the debian ftp command line
package (CWD) I get:
200 ok then a long wait then :
421 Service not available, remote server has closed connection.
I've tried this on two different FTP's and it only works if the firewall
is disactivated.
One server is a plesk server but the server I need to connect to I do
not know much about, with filezilla on my pc I've managed to connect to
it with both FTP active and FTP passive so I guess it can do both.
On my server I just do :
ftp ftp.server.com
username
password
So I'm not sure if it connects as passive or active.
These are the ports that I have got open :
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p tcp -m tcp --dport 20 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 21 -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 20 -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 21 -j ACCEPT
Which ports do you suggest I should open to connect to this FTP server ?
Thanks in advance,
Richard