The assumption here is that you “control” the router which runs Linux (iptables) and my guess is dnscrypt and inbound. What kind of HW are you using?
- pihole and unbound are running in a VM on an old intel NUC with an i5 and 18GB of RAM. The NUC is running Proxmox, and is connected to the edgerouter over ethernet
- Separately, there's a ubiquiti WAP and a standalone modem, but there's nothing special about their configuration
you could do it, but just because the USG software was a fork of Vyatta that had a way for doing it and Ubiquiti never put the effort to block it..
So while there was a way of doing it, it was never really officially supported..
But this is why when it came time to upgrade my USG3 i choose to migrate to Opnsense (pfsense fork) instead of upgrading to the latest Ubiquiti router.
UAP-AC-Lite for APs.
Dell PowerEdge R420 with proxmox hosting Opnsense as router, AdGuard Home for DNS, Unifi Controller hosted on Ubuntu and Home Assistant.