What is it? And what does it do?
Gradle sync is a gradle task that looks through all of your dependencies listed in your build.gradle files and tries to download the specified version.
Why does it needs internet connection? What ports does it use?
It requires an internet connection because it is usually downloading these dependencies from a remote location. You can define what ports it uses by changing your gradle.properties. (see below)
I'm working on an enterprise that has a proxy, and it fails trying to connect to somewhere.
Your work proxy may be blocking this and you'll need to add your proxy configuration to solve your issues.
Go into:
and update your proxy configuration url to your work proxy. (automatic or manual depending on your setup).
NOTE: If you are using the command line to run your gradle build, you will probably need to update the proxy settings via your gradle.properties file.
Global Properties File Location : ~/.gradle/gradle.properties (or use your local project file if you have one)
Add proxy settings to this file:
HTTPS
HTTP
If you absolutely cannot get an internet connection via gradle you'll need to download the dependencies another way and reference them locally on your computer or local network.
https://stackoverflow.com/questions/43636707/what-is-gradle-sync-in-android-studio?answertab=votes#tab-top