You could null route or firewall all the open resolvers, or at least the most common ones. If your router is linux, that might look like /sbin/ip route ad

You could null route or firewall all the open resolvers, or at least the most common ones. If your router is linux, that might look like /sbin/ip route add blackhole 9.9.9.9 2>/dev/null /sbin/ip route add blackhole 1.1.1.1 2>/dev/null /sbin/ip route add blackhole 1.0.0.1 2>/dev/null /sbin/ip route add blackhole 8.8.8.8 2>/dev/null /sbin/ip route add blackhole 8.8.4.4 2>/dev/null I'm probably leaving many of them off. There is probably a RBL for those by now. Here is one [1] and here is a list of them. [2] [1] - https://github.com/bambenek/block-doh https://github.com/bambenek/block-doh [2] - https://github.com/curl/curl/wiki/DNS-over-HTTPS https://github.com/curl/curl/wiki/DNS-over-HTTPS