We are working from the restricted network, where we setup the Jenkins server and it can be accessible within the Intranet only. The problem is that, Jenkins Can't download plugins - when we choose  the option "Download  now and Install after restart" button in Manage plugins. Whenever we try this, we are getting "Socket timeout exception". To enable this option in Jenkins tools, what all are the URL(s) to be white list from the firewall. 

Part of URL white list, we have enabled the URL (: https://updates.jenkins-ci.org/download/plugins/) . But this URL is not helping us to download plugins via tool.

It would be great helpful if someone can provide the exact URL's to be whitelist from firewall, so that Jenkins tool can download and install plugin automatically.