[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Iptables and FTP problem



Mahdi Rahimi a écrit :
my Rules for passive FTP look like this and works without problem but i
want to my LAN works in active ftp.

###control connection
$IPTABLES -A FORWARD -p tcp -s $LAN --sport 1024:65535 -d $EXT --dport 21
	-m state --state NEW,ESTABLISHED -j ACCEPT
$IPTABLES -A FORWARD -p tcp -s $EXT --sport 21 -d $LAN --dport 1024:65535
	 -m state --state RELATED,ESTABLISHED -j ACCEPT

RELATED is not needed for the control connections.

###data connection
$IPTABLES -A FORWARD -p tcp -s $LAN --sport 1024:65535 -d $EXT --dport
	1024:65535 -m state --state RELATED,ESTABLISHED -j ACCEPT
$IPTABLES -A FORWARD -p tcp -s $EXT --sport 1024:65535 -d $LAN --dport
	1024:65535 -m state --state RELATED,ESTABLISHED -j ACCEPT

This is getting confusing. In your previous messages, $LAN and $EXT were used in -i and -o options, meaning they contain interface names. Now they are used in -s and -d options, meaning they contain addresses or network address prefixes. So what are $LAN and $EXT ?

Assuming that $LAN and $EXT contain network prefixes (respectively 192.168.1.0/26 and 0.0.0.0/0 according to you previous messages), you need to add the following rules in order to allow transfers in active mode :

$IPTABLES -A FORWARD -p tcp -s $EXT --sport 20 -d $LAN \
  --dport 1024:65535 -m state --state RELATED,ESTABLISHED -j ACCEPT
$IPTABLES -A FORWARD -p tcp -s $LAN --sport 1024:65535 -d $EXT \
  --dport 20 -m state --state ESTABLISHED -j ACCEPT

However I recommend filtering at least on the input interface and not only on the source address, because the source address can be forged.



Reply to: