iptables -t nat -N prerouting_rule
iptables -t nat -N postrouting_rule
+iptables -N LAN_ACCEPT
+[ -z "$WAN" ] || iptables -A LAN_ACCEPT -i "$WAN" -j RETURN
+iptables -A LAN_ACCEPT -j ACCEPT
+
### INPUT
### (connections with the router as destination)
iptables -A INPUT -j input_rule
# allow
- iptables -A INPUT ${WAN:+-i \! $WAN} -j ACCEPT # allow from lan/wifi interfaces
+ iptables -A INPUT -j LAN_ACCEPT # allow from lan/wifi interfaces
iptables -A INPUT -p icmp -j ACCEPT # allow ICMP
iptables -A INPUT -p gre -j ACCEPT # allow GRE