To block ip addresses with Varnish edit the following file:

sudo nano /etc/varnish/default.vcl

And add the following. Of course replace the example ip addresses with the real ips you want to block.

acl forbidden {     "";     "";     "456.123.12.72"; } sub vcl_recv {     # Block access from these ips     if (client.ip ~ forbidden) {         error 403 "Forbidden";     } }

After editing, execute:

sudo service varnish restart