I am having trouble accessing proftpd through iptables. I've set up rules to allow tcp connections on ports 20 and 21. When I make a ftp connection the client says "Connected to abcd.com" and thats it no user prompt no nothing. I am using the default proftpd.conf that came with the installation. The strange thing is when I stop iptables everything works fine including logging and active file transfers. What could be the problem?


Rules copied from webmin for Incomming Packets(INPUT)
Accept If input interface is lo
Accept If protocol is TCP and destination ports are 80,443
Accept If protocol is TCP and destination ports are 20,21
Accept If protocol is TCP and destination ports are 22,25,3306,10000
Drop Always

You should post your iptables configuration so that others can verify.

Look through your proftpd.conf file for PassivePorts and note the ports listed. Now add a rule to Iptables to open those ports.

Look for a line similar to this in proftpd.conf:
PassivePorts 12345 12350

Add this line (change IP address and port numbers as needed) to iptables:
-A INPUT -s 192.168.1.0/255.255.255.0 -p tcp -m tcp --dport 12345:12350 -j ACCEPT