I need to allow ping from the WAN interface but from only a specific address. That's not an option in the web GUI so in an SSH terminal I entered the rules below (with correct IP address) but was still able to ping from any address. Are these rules correct, or am I missing something, or is this even possible? This on 3006.102.4 on an Asus RT-BE92U.
iptables -A INPUT -p icmp -j DROP
iptables -A INPUT -s 192.168.1.10 -p icmp -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p icmp -j DROP
iptables -A INPUT -s 192.168.1.10 -p icmp -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT