This problem has already been discribed before. But none of the suggested solutions work for me.
This is the problem:
I've got the latest version of Eclipse Luna (4.4.1) installed. If I want to do an update or install new software, it takes a very long time to complete (many HOURS). This is still the case if I download the desired software into a local archive/update site and install from there. But when I disable all network adapters and then install from such a "local" update site, the installation takes only a few seconds.
This "trick" to disable network adaptes can already be found as a proposed solution for the same question from 2010 here: Eclipse online access extremely slow--cannot complete updates or install new software. The accepted answer for this question does not help. I already disabled the "Contact all update sites" option and also added "-Declipse.p2.mirrors=false" to my eclipse.ini.
The disable-network-adapters-trick is no acceptable solution. Because I may not comment (reputation) I have to re-open the question.