Satellite 6 sync fails with 'Read timed out' or 'A connection error occurred' errors

Issue

• Satellite 6 repository sync fails with following errors.

Errors:
An error occurred during the sync 
{"url"=>"https://cdn.redhat.com/content/dist/rhel/server/7/7Server/x86_64/rh-common/os/Packages/r/rhel-guest-image-7-7.2-20160301.0.el7_2.noarch.rpm", "errors"=>["A connection error occurred"]}

Sep 6 05:18:41 satellite pulp: pulp_rpm.plugins.importers.iso.sync:ERROR: Failed to download https://cdn.redhat.com/content/dist/rhel/server/6/6Server/x86_64/iso/rhel-server-6.10-x86_64-dvd.iso: Download skipped.
....
Sep 6 05:26:38 satellite pulp: nectar.downloaders.threaded:ERROR: Skipping requests to cdn.redhat.com due to repeated connection failures: HTTPSConnectionPool(host='cdn.redhat.com', port=443): Read timed out.

• Packages as well as ISO sync fails with above errors.