I have observed that when this option is checked, it only permits LAN access to the DNS server, and if unchecked, neither LAN nor WAN access is allowed. To further investigate, I have allowed inbound traffic on port 53 (both UDP and TCP) from the WAN interface in the firewall: /ip firewall filter add action=accept chain=input dst-port=53 protocol=udp in-interface-list=WAN /ip firewall filter add action=accept chain=input dst-port=53 protocol=tcp in-interface-list=WAN. Despite this, I still do not see the Ros DNS server receiving DNS requests. My testing is being conducted on a local area network with my PC and the Ros device at the same level, with both connected to the same level router's LAN.