nic.cz https://odvr.nic.cz/dns-query DOH test 193.17.47.1 185.43.135.1 2001:148f:ffff::1 2001:148f:fffe::1 cloudflare https://cloudflare-dns.com/dns-query DOH test 1.1.1.1 1.0.0.1 2606:4700:4700::1111 2606:4700:4700::1001 google https://dns.google/dns-query DOH test 8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844