Hello, I need some hints for the following problem I have. I have seted up rules for SMTP and FTP server on a firewall and they work exept that I should whait 10 and more seconds before to get a responce from the server. I tryed to log all droped packates to see if there are some packtes which are related to smtp (or ftp) connection but there any. I have default policy DROP by default for the main chains: iptables -P INPUT DROP (OUTPUT,FORWARD) The rules in question are: ################### ### SMTP Server ### ################### iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_1 --dport 25 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_1 --dport 25 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_1 --dport 25 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_1 --dport 25 -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_1 --sport 25 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_2 --sport 25 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_3 --sport 25 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_4 --sport 25 --dport $UNPRIVPORTS -j ACCEPT and ################### ### FTP Server #### ################### #ftp iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_1 --dport 21 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_2 --dport 21 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_3 --dport 21 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_4 --dport 21 -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_1 --sport 21 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_2 --sport 21 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_3 --sport 21 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_4 --sport 21 --dport $UNPRIVPORTS -j ACCEPT #port mode iptables -A OUTPUT -o $INTERFACE -p tcp -s $LOCAL_IP_1 --sport 20 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp -s $LOCAL_IP_2 --sport 20 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp -s $LOCAL_IP_3 --sport 20 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp -s $LOCAL_IP_4 --sport 20 --dport $UNPRIVPORTS -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp ! --syn --sport $UNPRIVPORTS -d $LOCAL_IP_1 --dport 20 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp ! --syn --sport $UNPRIVPORTS -d $LOCAL_IP_2 --dport 20 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp ! --syn --sport $UNPRIVPORTS -d $LOCAL_IP_3 --dport 20 -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp ! --syn --sport $UNPRIVPORTS -d $LOCAL_IP_4 --dport 20 -j ACCEPT #passive mode iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_1 --dport $UNPRIVPORTS -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_2 --dport $UNPRIVPORTS -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_3 --dport $UNPRIVPORTS -j ACCEPT iptables -A INPUT -i $INTERFACE -p tcp --sport $UNPRIVPORTS -d $LOCAL_IP_4 --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_1 --sport $UNPRIVPORTS --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_2 --sport $UNPRIVPORTS --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_3 --sport $UNPRIVPORTS --dport $UNPRIVPORTS -j ACCEPT iptables -A OUTPUT -o $INTERFACE -p tcp ! --syn -s $LOCAL_IP_4 --sport $UNPRIVPORTS --dport $UNPRIVPORTS -j ACCEPT Thanks Vlady
