firewall basico

iptables -F
iptables -X
iptables -Z
iptables -t filter -F
iptables -t nat -F
iptables -t mangle -F
iptables -t filter -X
iptables -t nat -X
iptables -t mangle -X
iptables -t filter -Z
iptables -t nat -Z
iptables -t mangle -Z

iptables -P FORWARD ACCEPT
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT

echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -t nat -A POSTROUTING -o ! lo -j MASQUERADE