I'm trying to find out how to allow ping requests from just one public IP address (rather than any). I have unchecked the disable ping from internet (under system maintenance\management) and set up and ICMP firewall filter to allow requests from the one external IP address I want. I have then set up a filter to block ICMP from all other external addresses. The ping requests are still allowed from any public IP.
Is there a way of allowing pings from a restricted public IP address, or is it all or nothing?