diff --git a/ironic/common/exception.py b/ironic/common/exception.py
index 3c846f8d02..f9da690d18 100644
--- a/ironic/common/exception.py
+++ b/ironic/common/exception.py
@@ -190,6 +190,10 @@ class InvalidUUID(Invalid):
     message = _("Expected a uuid but received %(uuid)s.")
 
 
+class InvalidIdentity(Invalid):
+    message = _("Expected an uuid or int but received %(identity)s.")
+
+
 class InvalidMAC(Invalid):
     message = _("Expected a MAC address but received %(mac)s.")
 
diff --git a/ironic/common/utils.py b/ironic/common/utils.py
index a7c49c3205..2130ecabfe 100644
--- a/ironic/common/utils.py
+++ b/ironic/common/utils.py
@@ -297,7 +297,7 @@ def is_valid_boolstr(val):
 def is_valid_mac(address):
     """Verify the format of a MAC addres."""
     m = "[0-9a-f]{2}([-:])[0-9a-f]{2}(\\1[0-9a-f]{2}){4}$"
-    if re.match(m, address.lower()):
+    if isinstance(address, str) and re.match(m, address.lower()):
         return True
     return False
 
diff --git a/ironic/db/sqlalchemy/api.py b/ironic/db/sqlalchemy/api.py
index fc6f205a84..8f7480b63b 100644
--- a/ironic/db/sqlalchemy/api.py
+++ b/ironic/db/sqlalchemy/api.py
@@ -58,24 +58,38 @@ def model_query(model, *args, **kwargs):
     return query
 
 
-def add_uuid_filter(query, value):
+def add_identity_filter(query, value):
+    """Adds an identity filter to a query.
+
+    Filters results by ID, if supplied value is a valid integer.
+    Otherwise attempts to filter results by UUID.
+
+    :param query: Initial query to add filter to.
+    :param value: Value for filtering results by.
+    :return: Modified query.
+    """
     if utils.is_int_like(value):
         return query.filter_by(id=value)
     elif uuidutils.is_uuid_like(value):
         return query.filter_by(uuid=value)
     else:
-        raise exception.InvalidUUID(uuid=value)
+        raise exception.InvalidIdentity(identity=value)
 
 
 def add_port_filter(query, value):
-    if utils.is_int_like(value):
-        return query.filter_by(id=value)
-    elif utils.is_valid_mac(value):
+    """Adds a port-specific filter to a query.
+
+    Filters results by address, if supplied value is a valid MAC
+    address. Otherwise attempts to filter results by identity.
+
+    :param query: Initial query to add filter to.
+    :param value: Value for filtering results by.
+    :return: Modified query.
+    """
+    if utils.is_valid_mac(value):
         return query.filter_by(address=value)
-    elif uuidutils.is_uuid_like(value):
-        return add_uuid_filter(query, value)
     else:
-        raise exception.InvalidMAC(mac=value)
+        return add_identity_filter(query, value)
 
 
 class Connection(api.Connection):
@@ -109,7 +123,7 @@ class Connection(api.Connection):
             #             only if needed to determine the cause of an error.
             for node in nodes:
                 query = model_query(models.Node, session=session)
-                query = add_uuid_filter(query, node)
+                query = add_identity_filter(query, node)
 
                 # Be optimistic and assume we usually get a reservation.
                 count = query.filter_by(reservation=None).\
@@ -135,7 +149,7 @@ class Connection(api.Connection):
             #             only if needed to determine the cause of an error.
             for node in nodes:
                 query = model_query(models.Node, session=session)
-                query = add_uuid_filter(query, node)
+                query = add_identity_filter(query, node)
 
                 # be optimistic and assume we usually release a reservation
                 count = query.filter_by(reservation=tag).\
@@ -160,7 +174,7 @@ class Connection(api.Connection):
     @objects.objectify(objects.Node)
     def get_node(self, node):
         query = model_query(models.Node)
-        query = add_uuid_filter(query, node)
+        query = add_identity_filter(query, node)
 
         try:
             result = query.one()
@@ -188,7 +202,7 @@ class Connection(api.Connection):
         session = get_session()
         with session.begin():
             query = model_query(models.Node, session=session)
-            query = add_uuid_filter(query, node)
+            query = add_identity_filter(query, node)
 
             count = query.delete()
             if count != 1:
@@ -199,7 +213,7 @@ class Connection(api.Connection):
         session = get_session()
         with session.begin():
             query = model_query(models.Node, session=session)
-            query = add_uuid_filter(query, node)
+            query = add_identity_filter(query, node)
 
             print "Updating with %s." % values
             count = query.update(values, synchronize_session='fetch')
diff --git a/ironic/tests/db/test_nodes.py b/ironic/tests/db/test_nodes.py
index ec61e59d0e..d784e2df20 100644
--- a/ironic/tests/db/test_nodes.py
+++ b/ironic/tests/db/test_nodes.py
@@ -64,7 +64,7 @@ class DbNodeTestCase(base.DbTestCase):
         self.assertRaises(exception.NodeNotFound,
                           self.dbapi.get_node,
                           '12345678-9999-0000-aaaa-123456789012')
-        self.assertRaises(exception.InvalidUUID,
+        self.assertRaises(exception.InvalidIdentity,
                           self.dbapi.get_node, 'not-a-uuid')
 
     def test_get_node_by_instance(self):
diff --git a/ironic/tests/db/test_ports.py b/ironic/tests/db/test_ports.py
index dd25330964..a16b613776 100644
--- a/ironic/tests/db/test_ports.py
+++ b/ironic/tests/db/test_ports.py
@@ -52,7 +52,7 @@ class DbPortTestCase(base.DbTestCase):
                           self.dbapi.get_port, 99)
         self.assertRaises(exception.PortNotFound,
                           self.dbapi.get_port, 'aa:bb:cc:dd:ee:ff')
-        self.assertRaises(exception.InvalidMAC,
+        self.assertRaises(exception.InvalidIdentity,
                           self.dbapi.get_port, 'not-a-mac')
 
     def test_get_ports_by_node_id(self):