I'm using HaGeZi's Ultimate DNS Blocklist with AdAway as a base and am now trying to add my own "tweaks", according to what connections my phone makes.

I set PCAPdroid to automatically start capturing after reboot. Before reboot, I kill-ed as many apps and processes as possible without crashing Android and then cleared system memory. I then rebooted and left the phone untouched for five minutes. The following is a heavily edited excerpt of the resulting pcap file. I removed the source IPs, ports, package sizes and protocols, so that the excerpt only contains the destination hosts and the "issuing" apps/packages.

**Google Play Services**
playatoms-pa.googleapis.com
digitalassetlinks.googleapis.com
www.googleapis.com
mtalk.google.com
android.googleapis.com

**Google Play Store**
play-fe.googleapis.com
play.googleapis.com

**IronFox**
firefox.settings.services.mozilla.com
firefox-settings-attachments.cdn.mozilla.net
content-signature-2.cdn.mozilla.net

**Android**
es11.samsung-sm-ds.com

Here are four screenshots of the PCAPdroid capture, in which you additionally can see the protocols, destination ports, captured times, packet sizes and connection states. Let me know if the Buzzheavier link is broken.

Do you have any insights regarding these hosts? What they do, whether they are necessary for an Android system that still runs on the proprietary Google libraries and Google Play Services or whether they can be blocked? I am already blocking the Play Store with a firewall, so the hosts associated with it might not even be getting through. Unfortunately, my firewall doesn't come with granular enough control to allow blocking of individual hosts, which I guess I could do with AdAway instead and see what happens. Anyway, lend me your wisdom! :)