after the upgrade from debian squeeze to wheezy I've got a problem with passive FTP connection. I could narrow it to be iptables related, as I could connect via FTP w/o problems after adding my IP to the iptables ACCEPT rule. Before the upgrade I was able just to do modprobe nf_conntract_ftp ports=21332 and adding iptables -A THRU -p tcp --dport 21332 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT now..it doesn't help anymore. The INPUT rule is being triggered as I can see in the counter, but the directory listing is the last thing it does. Setting up a passive-port range is the last thing I want to do, I dislike open ports. I also tried the trick with helper mod by adding following rule before the actual rule for 21332 iptables -A THRU -p tcp -i eth0 --dport 21332 -m state --state NEW -m helper --helper ftp-21332 -j ACCEPT but it doesn't help and is even not being triggered according to counter. The rule in the next line (w/o helper) is being triggered.. here some info: # iptables --version iptables v1.4.14 # lsmod |grep nf_ nf_nat_ftp 12460 0 nf_nat 18242 1 nf_nat_ftp nf_conntrack_ftp 12605 1 nf_nat_ftp nf_conntrack_ipv4 14078 32 nf_nat nf_defrag_ipv4 12483 1 nf_conntrack_ipv4 nf_conntrack 52720 7 xt_state,nf_conntrack_ipv4,xt_conntrack,nf_conntrack_ftp,nf_nat,nf_nat_ftp,xt_helper # uname -a Linux loki 3.2.0-4-amd64 #1 SMP Debian 3.2.46-1 x86_64 GNU/Linux # iptables-save # Generated by iptables-save v1.4.14 on Sun Jun 30 03:54:28 2013 *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] :BLACKLIST - [0:0] :LOGDROP - [0:0] :SPAM - [0:0] :THRU - [0:0] :WEB - [0:0] :fail2ban-dovecot-pop3imap - [0:0] :fail2ban-pureftpd - [0:0] :fail2ban-ssh - [0:0] -A INPUT -p tcp -m multiport --dports 110,995,143,993 -j fail2ban-dovecot-pop3imap -A INPUT -p tcp -m multiport --dports 21,21332 -j fail2ban-pureftpd -A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh -A INPUT -p tcp -m multiport --dports 110,995,143,993 -j fail2ban-dovecot-pop3imap -A INPUT -i lo -j ACCEPT -A INPUT -i eth0 -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -j DROP -A INPUT -i eth0 -p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -j DROP -A INPUT -i eth0 -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -j DROP -A INPUT -i eth0 -p tcp -m tcp --tcp-flags FIN,RST FIN,RST -j DROP -A INPUT -i eth0 -p tcp -m tcp --tcp-flags FIN,ACK FIN -j DROP -A INPUT -i eth0 -p tcp -m tcp --tcp-flags ACK,URG URG -j DROP -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -A INPUT -j BLACKLIST -A INPUT -j THRU -A INPUT -j LOGDROP -A OUTPUT -j ACCEPT -A OUTPUT -s 93.223.38.223/32 -j ACCEPT -A BLACKLIST -s 38.113.165.0/24 -j LOGDROP -A BLACKLIST -s 202.177.216.0/24 -j LOGDROP -A BLACKLIST -s 130.117.190.0/24 -j LOGDROP -A BLACKLIST -s 117.79.92.0/24 -j LOGDROP -A BLACKLIST -s 72.47.228.0/24 -j LOGDROP -A BLACKLIST -s 195.200.70.0/24 -j LOGDROP -A BLACKLIST -s 195.200.71.0/24 -j LOGDROP -A LOGDROP -m limit --limit 5/sec -j LOG --log-prefix drop_packet_ --log-level 7 -A LOGDROP -p tcp -m tcp --dport 25 -m limit --limit 2/sec -j LOG --log-prefix spam_blacklist --log-level 7 -A LOGDROP -p tcp -m tcp --dport 80 -m limit --limit 2/sec -j LOG --log-prefix web_blacklist --log-level 7 -A LOGDROP -p tcp -m tcp --dport 22 -m limit --limit 2/sec -j LOG --log-prefix ssh_blacklist --log-level 7 -A LOGDROP -j REJECT --reject-with icmp-host-prohibited -A THRU -p icmp -m limit --limit 1/sec -m icmp --icmp-type 8 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 25 -j ACCEPT -A THRU -i eth0 -p udp -m udp --dport 53 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 80 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 110 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 143 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 465 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 585 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 993 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 995 -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 2008 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 10011 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 21332 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A THRU -i eth0 -p tcp -m tcp --dport 30033 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A fail2ban-dovecot-pop3imap -j RETURN -A fail2ban-dovecot-pop3imap -j RETURN -A fail2ban-pureftpd -j RETURN -A fail2ban-pureftpd -j RETURN -A fail2ban-ssh -j RETURN -A fail2ban-ssh -j RETURN COMMIT # Completed on Sun Jun 30 03:54:28 2013 So, as I said, I have no problems with connecting when adding my IP to go through..but that's not a solution as noone except me can connect anymore~ If someone got an idea what the problem is, please help me! Thanks Cracky