https://analytics.googleblog.com/2017/01/the-new-google-data...
"Notes
Currently this connector does not support SSL. Be careful with the data you send.
If you database is behind a firewall, you will need to open access to the following IP addresses so that Data Studio can access your database:
64.18.0.0/20
64.233.160.0/19
[... cut 10 other addresses ...]
216.239.32.0/19"
How exactly did this make it into a public Google release?
"Notes
Currently this connector does not support SSL. Be careful with the data you send.
If you database is behind a firewall, you will need to open access to the following IP addresses so that Data Studio can access your database:
64.18.0.0/20
64.233.160.0/19
[... cut 10 other addresses ...]
216.239.32.0/19"