no external_ip grain, any add-on grain will need to use

a different function name

salt/loader.py

@@ -1204,6 +1204,8 @@ class Loader(object):
         grains_data = {}
         funcs = self.gen_functions()
         for key, fun in funcs.items():
+            if key and fun == 'external_ip':
+                continue
             if key[key.index('.') + 1:] == 'core':
                 continue
             try: