When I start the iptables service, there is no ftp access because of a connection timeout. When I stop the iptables service, ftp works fine.
This is the current iptables data:
Update: replaced ESTABLISHED for NEW in p21 rule. The problem is still happening.
# Generated by iptables-save v1.4.7 on Sun Dec 14 23:48:26 2014
*filter
:INPUT DROP [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [4:2848]
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -j DROP
-A INPUT -p tcp -m tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m state --state NEW -j DROP
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN,SYN,RST,PSH,ACK,URG -j DROP
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m tcp --sport 21 -m state --state NEW -j ACCEPT
-A INPUT -p tcp -m tcp --sport 20 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --sport 1024:65535 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 21 -m state --state NEW,ESTABLISHED -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 20 -m state --state ESTABLISHED -j ACCEPT
-A OUTPUT -p tcp -m tcp --sport 1024:65535 --dport 1024:65535 -m state --state RELATED,ESTABLISHED -j ACCEPT
COMMIT
# Completed on Sun Dec 14 23:48:26 2014
Could any of these lines causing this strange behavior?
-A INPUT -p tcp -m tcp --sport 21 -m state --state ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --sport 20 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --sport 1024:65535 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 21 -m state --state NEW,ESTABLISHED -j ACCEPT
-A OUTPUT -p tcp -m tcp --dport 20 -m state --state ESTABLISHED -j ACCEPT
-A OUTPUT -p tcp -m tcp --sport 1024:65535 --dport 1024:65535 -m state --state RELATED,ESTABLISHED -
I've tried connecting to the ftp server in both passive and active modes.