Just some info for new folks if you wish to chnge the default DNS servers on your system. After a little bit of searching & trail and error, I’ve discovered how to modify Antergos so that you can use DNS servers other than those which might be supplied by your ISP.

Two files need to be edited:
/etc/resolv.conf
/etc/NetworkManager/NetworkManager.conf

First backup both of these files in case something goes wrong.

Edit /etc/resolv.conf to specify the DNS servers you wish to use (this example uses DNS.WATCH servers):

nameserver 84.200.69.80
nameserver 2001:1608:10:25::1c04:b12f

Then, edit /etc/NetworkManager/NetworkManager.conf to tell it NOT to overwrite resolv.conf, by adding a [main] section which includes dns=none :

[main]
dns=none

Verify this works by rebooting and checking the contents of /etc/resolve.conf.

Then verify that the resolvers are working by browsing the web or using drill:

drill google.com
;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 61859
;; flags: qr rd ra ; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;; google.com. IN A