# defaults
$IPT -t filter -A INPUT -p icmp -j ACCEPT
-$IPT -t filter -A INPUT -p 47 -j ACCEPT
+$IPT -t filter -A INPUT -p 47 -j ACCEPT # allow GRE
+$IPT -t filter -A INPUT -i $WAN -p tcp --syn --tcp-option \! 2 -j DROP
$IPT -t filter -A INPUT -i $WAN -p tcp -j REJECT --reject-with tcp-reset
$IPT -t filter -A INPUT -i $WAN -j REJECT --reject-with icmp-port-unreachable
-$IPT -t filter -A FORWARD -i $WAN -m state --state NEW,INVALID -j DROP
+$IPT -t filter -A FORWARD -i br0 -o br0 -j ACCEPT
+$IPT -t filter -A FORWARD -i $WAN -m state --state NEW -j DROP
$IPT -t filter -A FORWARD -o $WAN -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
$IPT -t nat -A POSTROUTING -o $WAN -j MASQUERADE