Syncing external reporitories to Satellite 5.x fails with "Cannot retrieve repository metadata (repomd.xml) for repository"

Issue

• In order to create an EPEL channel and repository I followed the instructions on https://access.redhat.com/solutions/308983.
• Ok, somehow when I start up the sync, I recieve an error telling me the URL is not correct and the repomd.xml cannot be found.

• Sync Output:

  Sync started: Thu Nov 13 12:08:48 2014
  ['/usr/bin/spacewalk-repo-sync', '--channel', 'epel_rhel6_x86_64_v1', '--type', 'yum']
  Repo URL: http://mirrors.nl.kernel.org/fedora-epel/6Server/x86_64/
  ERROR: Cannot retrieve repository metadata (repomd.xml) for repository: epel_rhel6_x86_64_v1. Please verify its path and try again
  Sync completed.
  Total time: 0:00:00
  

• In order to exclude an internal Firewall issue, and as far as I can tell the used URL is valid and reachable from the Satellite test server