Use a DNS blocklist

A DNS blocklist is a hosts file mapping domains you want to block to 0.0.0.0 (to block it over IPv4), ::0 (to block it over IPv6), or both.

For example, a hosts file containing the following two lines would block example.com over both IPv4 and IPv6:

0.0.0.0 example.com
::0 example.com

For a much larger example, see Steven Black's hosts file which begins with:

#=====================================
# Title: Hosts contributed by Steven Black
# http://stevenblack.com

0.0.0.0 ck.getcookiestxt.com
0.0.0.0 eu1.clevertap-prod.com
0.0.0.0 wizhumpgyros.com
0.0.0.0 coccyxwickimp.com
0.0.0.0 webmail-who-int.000webhostapp.com

And then has many more entries.

If you have a DNS blocklist in some other format (for example, just a list of domains to block) you'll need to convert it into a hosts file (or a zone file) first.

Once you have your hosts file, configure resolved to use it with the -a or -A options:

• resolved -a /path/to/directory/file
• resolved -A /path/to/directory

I recommend the -A form, as you can then add or remove hosts files to the directory and send SIGUSR1 to resolved to reload the hosts files without restarting the process.