By default, a server set up will defer authentication to the Mozilla-hosted accounts server at [https://accounts.firefox.com](https://accounts.firefox.com). So you will still have to authenticate at Mozilla, but _the storage of your information will be done on your host_.
The sure-fire way to know what Sync on Android is really doing is to observe the Android device log using adb logcat. You’ll want to bump your log-level:
```
adb shell setprop log.tag.FxAccounts VERBOSE
```
Then, you can observe the log using:
```
adb logcat | grep FxAccounts
```
It’s best to observe the log while you force a sync from the Android Settings App. You should see output like:
```
D FxAccounts(...) fennec :: BaseResource :: HTTP GET https://token.stage.mozaws.net/1.0/sync/1.5
...
D FxAccounts(...) fennec :: BaseResource :: HTTP GET https://sync-4-us-east-1.stage.mozaws.net/