diff --git a/uncloud/hack/mac.py b/uncloud/hack/mac.py
index e7f41a2..084df13 100755
--- a/uncloud/hack/mac.py
+++ b/uncloud/hack/mac.py
@@ -38,7 +38,8 @@ class MAC(object):
         self.config = config
         self.db = DB(config, prefix="/mac")
 
-        self.prefix = 0x002000000000
+        self.prefix = 0x420000000000
+        self._number = 0 # Not set by default
 
     @staticmethod
     def validate_mac(mac):
@@ -56,35 +57,40 @@ class MAC(object):
     def last_used_mac(self):
         return self.int_to_mac(self.prefix + self.last_used_index())
 
-    @staticmethod
-    def int_to_mac(number):
-        b = number.to_bytes(6, byteorder="big")
+    def to_colon_format(self):
+        b = self._number.to_bytes(6, byteorder="big")
         return ':'.join(format(s, '02x') for s in b)
 
-    def get_next(self, vmuuid=None, as_int=False):
+    def to_str_format(self):
+        b = self._number.to_bytes(6, byteorder="big")
+        return ''.join(format(s, '02x') for s in b)
+
+    def create(self):
         last_number = self.last_used_index()
 
-        # FIXME: compare to 48bit minus prefix length to the power of 2
-        if last_number == int('0xffffff', 16):
+        if last_number == int('0xffffffff', 16):
             raise UncloudException("Exhausted all possible mac addresses - try to free some")
 
         next_number = last_number + 1
-        next_number_string = "{:012x}".format(next_number)
+        self._number = self.prefix + next_number
 
-        next_mac_number = self.prefix + next_number
-        next_mac = self.int_to_mac(next_mac_number)
-
-        db_entry = {}
-        db_entry['vm_uuid'] = vmuuid
-        db_entry['index'] = next_number
-        db_entry['mac_address'] = next_mac
+        #next_number_string = "{:012x}".format(next_number)
+        #next_mac = self.int_to_mac(next_mac_number)
+        # db_entry = {}
+        # db_entry['vm_uuid'] = vmuuid
+        # db_entry['index'] = next_number
+        # db_entry['mac_address'] = next_mac
 
         # should be one transaction
-        self.db.increment("last_used_index")
-        self.db.set("used/{}".format(next_mac),
-                    db_entry, as_json=True)
+        # self.db.increment("last_used_index")
+        # self.db.set("used/{}".format(next_mac),
+        #             db_entry, as_json=True)
 
-        if as_int:
-            return next_mac_number
-        else:
-            return next_mac
+    def __int__(self):
+        return self._number
+
+    def __repr__(self):
+        return self.to_str_format()
+
+    def __str__(self):
+        return self.to_colon_format()