iptables -F INPUT iptables -F OUTPUT iptables -F FORWARD
iptables -t filter -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
iptables -P INPUT DROP iptables -P OUTPUT ACCEPT iptables -P FORWARD DROP
iptables -t filter -A INPUT -p tcp -m tcp --dport 25 -j ACCEPT
iptables -t filter -A INPUT -p udp -m udp --dport 53 -j ACCEPT
iptables -t filter -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
iptables -t filter -A INPUT -p tcp -m tcp --dport 110 -j ACCEPT
iptables -t filter -A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
iptables -t filter -A INPUT -p tcp -m tcp --sport 25 -j ACCEPT
iptables -t filter -A INPUT -p udp -m udp --sport 53 -j ACCEPT
iptables -t filter -A INPUT -s 123.123.123.123 -p tcp -m tcp --dport 22 -j ACCEPT
iptables -t filter -A INPUT -d 234.234.234.234 -p tcp -m tcp --dport 22 -j ACCEPT
iptables -t filter -A INPUT -s 123.123.123.123 -d 234.234.234.234 -p tcp -m tcp --dport 22 -j ACCEPT
iptables -t filter -A INPUT -i eth0 -s 123.123.123.123 -p tcp -m tcp --dport 22 -j ACCEPT
iptables -t filter -A INPUT -p tcp -m tcp --dport 20 -m state --state RELATED,ESTABLISHED -j ACCEPT iptables -t filter -A INPUT -p tcp -m tcp --dport 21 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -N FIREWALL_CHAIN_1
iptables -t filter -A INPUT -s 192.168.0.0/24 -p tcp -m tcp -j FIREWALL_CHAIN_1
iptables -t filter -A FIREWALL_CHAIN_1 -p tcp -m tcp --dport 80 -j ACCEPT
net.ipv4.ip_forward=1
echo "1" >/proc/sys/net/ipv4/ip_forward
iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -d ! 192.168.0.0/24 -j MASQUERADE
iptables -t nat -A POSTROUTING -s 192.168.2.0/24 -d 192.168.0.0/24 -j MASQUERADE
iptables -t nat -A PREROUTING -d 192.168.0.1/32 -p tcp -m tcp --dport 80 -j DNAT --to-destination 127.0.0.1:80
iptables -t nat -A POSTROUTING -s 127.0.0.1/32 -p tcp -m tcp --dport 80 -j SNAT --to-source 192.168.0.1
iptables -t nat -A PREROUTING -d 192.168.100.25/32 -p tcp -m tcp --dport 3389 -j DNAT --to-destination 192.168.0.15:3389 iptables -t nat -A POSTROUTING -s 192.168.0.15/32 -p tcp -m tcp --dport 3389 -j SNAT --to-source 192.168.100.25
iptables -F FORWARD
iptables -A FORWARD -i eth0 -o eth1 -j ACCEPT iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT iptables -A FORWARD -i eth0 -o eth2 -j ACCEPT iptables -A FORWARD -i eth2 -o eth0 -j ACCEPT iptables -A FORWARD -i eth1 -o eth2 -j DROP iptables -A FORWARD -i eth2 -o eth1 -j DROP
iptables -A FORWARD -i eth1 -o eth2 -j DROP iptables -A FORWARD -i eth2 -o eth1 -j DROP
