#Rede Interna
REDE_INTERNA=192.168.1.0/24
#Ativar modulos
modprobe iptable_nat
modprobe ip_conntrack
modprobe ip_nat_ftp
#Matando Firewall
iptables -F
iptables -Z
iptables -X
iptables -t nat -F
#Dropando todos os Policiamentos
iptables -P INPUT DROP
iptables -P FORWARD DROP
#Compartilhar a Internet
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
echo 1 > /proc/sys/net/ipv4/ip_forward
#Proteger contra syn flood
echo 1 > /proc/sys/net/ipv4/tcp_syncookies
#Redirecionando para o Squid
iptables -t nat -A PREROUTING -i eth1 -s $REDE_INTERNA -p tcp --dport 80 -j REDIRECT --to-port 3128
#Regras INPUT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i eth1 -s $REDE_INTERNA -j ACCEPT
iptables -A INPUT -i eth1 -s $REDE_INTERNA -p icmp -j ACCEPT
#Regras Forward
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -o eth0 -s $REDE_INTERNA -j ACCEPT
iptables -A FORWARD -o eth0 -s $REDE_INTERNA -p icmp -j ACCEPT
echo "Levantando Firewall..."