iptables -t nat -A PREROUTING -j prerouting_rule
[ -z "$WAN" ] || iptables -t nat -A PREROUTING -i "$WAN" -j prerouting_wan
iptables -t nat -A POSTROUTING -j postrouting_rule
- [ -z "$WAN" ] || iptables -t nat -A POSTROUTING -o $WAN -j MASQUERADE
+ ### Only RFC1918 addresses
+ [ -z "$WAN" ] || iptables -t nat -A POSTROUTING --src 192.168.0.0/16 -o $WAN -j MASQUERADE
+ [ -z "$WAN" ] || iptables -t nat -A POSTROUTING --src 172.16.0.0/12 -o $WAN -j MASQUERADE
+ [ -z "$WAN" ] || iptables -t nat -A POSTROUTING --src 10.0.0.0/8 -o $WAN -j MASQUERADE
iptables -t nat -A NEW -m limit --limit 50 --limit-burst 100 -j RETURN && \
iptables -t nat -A NEW -j DROP