Newbie questions

Linking your public IP merely authorizes your network; it does not route your traffic. You absolutely must configure your router's DHCP server to distribute the NextDNS IPv4 addresses to all WiFi clients. Without this DHCP configuration, your clients will continue to default to the ISP's resolver. This is a fundamental rule of network topology.

Regarding internal client tracking: It is technically impossible to track or filter by internal LAN IPs using only a Linked Public IP. This is due to NAT (Network Address Translation). NAT strips all local IP identifiers and masquerades your entire local network behind that single public WAN IP. To the NextDNS servers, your entire house appears as one single device.

To achieve granular, per-device tracking, you have exactly two irrefutable technical solutions. There is no magic workaround for NAT:

 1. Deploy the NextDNS CLI on the Router: If your router supports it (e.g., OpenWrt, Asuswrt-Merlin, pfSense), you must install the NextDNS daemon. The CLI intercepts local DNS queries and appends the client's MAC address or internal LAN IP to the payload before forwarding it to the upstream server.

 2. Native Client Configuration: If your router does not support the CLI, you must manually configure DoH/DoT (Private DNS) or install the NextDNS application natively on every single individual device.

You either bypass the NAT limitation at the router level via the CLI, or you configure the endpoints individually. Those are the only architectural realities.