I have set up several iptables rules , and at the end I set The Policies to Drop But It will Drop every thing even my rules
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -p tcp -s 127.0.0.1 --dport 3306 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -d 127.0.0.1 --dport 3306 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s x.x.x.x --dport 3306 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -s 127.0.0.1 -p tcp -m state --state NEW,ESTABLISHED -m multiport --sports 110,25,143 -j ACCEPT
iptables -A INPUT -p tcp -s x.x.x.x --dport 3690 -j ACCEPT
iptables -A OUTPUT -p tcp -s 127.0.0.1 --sport 3690 -j ACCEPT
iptables -A INPUT -p tcp -s 0/0 --sport 80 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s x.x.x.x --sport 22 --dport 22 -j ACCEPT
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP
but I cant access my website or ssh . Please help, thanks in advance
Iptables -nvL :
Chain INPUT (policy ACCEPT 3158 packets, 285K bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT tcp -- * * 127.0.0.1 0.0.0.0/0
tcp dpt:3306 state NEW,ESTABLISHED
0 0 ACCEPT tcp -- * * 82.115.26.145 0.0.0.0/0 tcp dpt:3306 state NEW,ESTABLISHED
0 0 ACCEPT tcp -- * * 82.115.26.145 0.0.0.0/0 tcp dpt:3690
0 0 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp spt:80 state NEW,ESTABLISHED
0 0 ACCEPT tcp -- * * 82.115.26.145 0.0.0.0/0 tcp spt:22 dpt:22
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
Chain OUTPUT (policy ACCEPT 1152 packets, 160K bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- * lo 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT tcp -- * * 0.0.0.0/0 127.0.0.1 tcp dpt:3306 state NEW,ESTABLISHED
0 0 ACCEPT tcp -- * * 127.0.0.1 0.0.0.0/0 state NEW,ESTABLISHED multiport sports 110,25,143
0 0 ACCEPT tcp -- * * 127.0.0.1 0.0.0.0/0 tcp spt:3690
but assume the policy is DROP for all chains
You have the fundamentals there but they are a little mixed up. INPUT needs a source ip and destination port and OUTPUT needs a destination ip and source port. Traffic coming in will be NEW or ESTABLISHED and traffic going out from server services (in a client/server design) will be ESTABLISHED.
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -p tcp -s x.x.x.x --dport 3306 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -d x.x.x.x --sport 3306 -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s x.x.x.x --dport 3690 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -d x.x.x.x --sport 3690 -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp --sport 80 -m state --state ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s x.x.x.x --dport 22 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -d x.x.x.x --sport 22 -m state --state ESTABLISHED -j ACCEPT
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP