Why does Eclipse P2 download files from eclipse.org every time?

Question

When installing or updating plug-ins, the update system of Eclipse always fetch some jar/xml files from eclipse.org, this annoying behavior slows down the update process.

Is there any way to disable it?

Answer 1

Eclipse should only contact the sites declared in the "Available Softwares Sites" list:

For instance, in the list above, we have removed all references to eclipse.org, and disabled direct p2 repo addresses, and left only references to out own internal Nexus pro repository (which is able to mirror remote p2 site)