Issue

# subscription-manager repos --enable rhel-5-server-els-rpms
Network error, unable to connect to server. Please see /var/log/rhsm/rhsm.log for more information.

The /var/log/rhsm/rhsm.log contains entries like the following:

2017-08-06 04:02:03,753 [DEBUG] rhsmd @connection.py:451 - Making request: PUT /subscription/consumers/0a1b2c3d-0a1b-0a1b-0a1b-0a1b2c3d4e5f
2017-08-06 04:02:03,754 [ERROR] rhsmd @cache.py:181 - Error updating system data on the server
2017-08-06 04:02:03,754 [ERROR] rhsmd @cache.py:182 - (-3, 'Temporary failure in name resolution')
Traceback (most recent call last):
  File "/usr/share/rhsm/subscription_manager/cache.py", line 173, in update_check
    self._sync_with_server(uep, consumer_uuid)
  File "/usr/share/rhsm/subscription_manager/cache.py", line 460, in _sync_with_server
    installed_products=self.format_for_server())
  File "/usr/lib64/python2.4/site-packages/rhsm/connection.py", line 800, in updateConsumer
    ret = self.conn.request_put(method, params)
  File "/usr/lib64/python2.4/site-packages/rhsm/connection.py", line 564, in request_put
    return self._request("PUT", method, params)
  File "/usr/lib64/python2.4/site-packages/rhsm/connection.py", line 458, in _request
    conn.request(request_type, handler, body=body, headers=headers)
  File "/usr/lib64/python2.4/httplib.py", line 810, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib64/python2.4/httplib.py", line 833, in _send_request
    self.endheaders()
  File "/usr/lib64/python2.4/httplib.py", line 804, in endheaders
    self._send_output()
  File "/usr/lib64/python2.4/httplib.py", line 685, in _send_output
    self.send(msg)
  File "/usr/lib64/python2.4/httplib.py", line 652, in send
    self.connect()
  File "/usr/lib64/python2.4/site-packages/M2Crypto/httpslib.py", line 49, in connect
    for (family, _, _, _, _) in \
gaierror: (-3, 'Temporary failure in name resolution')
2017-08-06 04:02:03,755 [DEBUG] rhsmd @cert_sorter.py:335 - Failed to sync installed products with the server
2017-08-06 04:02:03,755 [DEBUG] rhsmd @cert_sorter.py:336 - Error updating system data on the server, see /var/log/rhsm/rhsm.log for more details.