diff --git a/ietf/__init__.py b/ietf/__init__.py
index 2f629c3ce..bcac7a1da 100644
--- a/ietf/__init__.py
+++ b/ietf/__init__.py
@@ -1,7 +1,12 @@
 # Copyright The IETF Trust 2007, All Rights Reserved
+import checks                           # pyflakes:ignore
 
+# Don't add patch number here:
 __version__ = "6.2.1.dev0"
 
+# set this to ".p1", ".p2", etc. after patching
+__patch__   = ""                        
+
 __date__    = "$Date$"
 
 __rev__     = "$Rev$ (dev) Latest release: Rev. 9880 "
diff --git a/ietf/checks.py b/ietf/checks.py
new file mode 100644
index 000000000..4f9c789ef
--- /dev/null
+++ b/ietf/checks.py
@@ -0,0 +1,22 @@
+import os
+
+from django.conf import settings
+from django.core import checks
+
+@checks.register('directories')
+def check_cdn_directory_exists(app_configs, **kwargs):
+    """This checks that the path from which the CDN will serve static files for
+       this version of the datatracker actually exists.  In development and test
+       mode this will normally be just STATIC_ROOT, but in production it will be
+       a symlink to STATIC_ROOT, with a path containing the datatracker release
+       version.
+    """
+    errors = []
+    if not os.path.exists(settings.STATIC_CDN_PATH):
+        errors.append(checks.Error(
+            'The CDN static files path has not been set up',
+            hint='Set up this symlink:\n\t%s -> %s' % (settings.STATIC_CDN_PATH, settings.STATIC_ROOT),
+            obj=None,
+            id='datatracker.E001',
+        ))
+    return errors
diff --git a/ietf/context_processors.py b/ietf/context_processors.py
index 7db015432..29b50b209 100644
--- a/ietf/context_processors.py
+++ b/ietf/context_processors.py
@@ -1,7 +1,7 @@
 # Copyright The IETF Trust 2007, All Rights Reserved
 
 from django.conf import settings
-from ietf import __date__, __rev__, __version__, __id__
+from ietf import __date__, __rev__, __version__, __patch__, __id__
 
 def server_mode(request):
     return {'server_mode': settings.SERVER_MODE}
@@ -10,4 +10,4 @@ def rfcdiff_base_url(request):
     return {'rfcdiff_base_url': settings.RFCDIFF_BASE_URL}
     
 def revision_info(request):
-    return {'revision_time': __date__[7:32], 'revision_date': __date__[7:17], 'revision_num': __rev__[6:-2], "revision_id": __id__[5:-2], "version_num": __version__ }
+    return {'revision_time': __date__[7:32], 'revision_date': __date__[7:17], 'revision_num': __rev__[6:-2], "revision_id": __id__[5:-2], "version_num": __version__+__patch__ }
diff --git a/ietf/settings.py b/ietf/settings.py
index 9cb472168..e0e6e98bb 100644
--- a/ietf/settings.py
+++ b/ietf/settings.py
@@ -108,8 +108,10 @@ SERVE_CDN_FILES_LOCALLY_IN_DEV_MODE = True
 # URL to use when referring to static files located in STATIC_ROOT.
 if SERVER_MODE != 'production' and SERVE_CDN_FILES_LOCALLY_IN_DEV_MODE:
     STATIC_URL = "/lib/"
+    STATIC_CDN_PATH = STATIC_ROOT
 else:
     STATIC_URL = "https://www.ietf.org/lib/dt/%s/"%__version__
+    STATIC_CDN_PATH = "/a/www/www6s/lib/dt/%s/"%__version__
 
 # Destination for components handled by djangobower
 COMPONENT_ROOT = STATIC_ROOT
@@ -119,7 +121,7 @@ COMPONENT_ROOT = STATIC_ROOT
 STATICFILES_FINDERS = (
     'django.contrib.staticfiles.finders.FileSystemFinder',
     'django.contrib.staticfiles.finders.AppDirectoriesFinder',
-    'ietf.storage.CdnStorageFinder',
+    'ietf.utils.storage.CdnStorageFinder',
 )