diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index 756f1bc38..1cb71d803 100644
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -132,7 +132,7 @@ def v4_int_to_packed(address):
 
     """
     try:
-        return address.to_bytes(4, 'big')
+        return address.to_bytes(4)  # big endian
     except OverflowError:
         raise ValueError("Address negative or too large for IPv4")
 
@@ -148,7 +148,7 @@ def v6_int_to_packed(address):
 
     """
     try:
-        return address.to_bytes(16, 'big')
+        return address.to_bytes(16)  # big endian
     except OverflowError:
         raise ValueError("Address negative or too large for IPv6")
 
@@ -1077,15 +1077,16 @@ class _BaseNetwork(_IPAddressBase):
 
     @property
     def is_private(self):
-        """Test if this address is allocated for private networks.
+        """Test if this network belongs to a private range.
 
         Returns:
-            A boolean, True if the address is reserved per
+            A boolean, True if the network is reserved per
             iana-ipv4-special-registry or iana-ipv6-special-registry.
 
         """
-        return (self.network_address.is_private and
-                self.broadcast_address.is_private)
+        return any(self.network_address in priv_network and
+                   self.broadcast_address in priv_network
+                   for priv_network in self._constants._private_networks)
 
     @property
     def is_global(self):
@@ -1122,6 +1123,15 @@ class _BaseNetwork(_IPAddressBase):
         return (self.network_address.is_loopback and
                 self.broadcast_address.is_loopback)
 
+
+class _BaseConstants:
+
+    _private_networks = []
+
+
+_BaseNetwork._constants = _BaseConstants
+
+
 class _BaseV4:
 
     """Base IPv4 object.
@@ -1294,7 +1304,7 @@ class IPv4Address(_BaseV4, _BaseAddress):
         # Constructing from a packed address
         if isinstance(address, bytes):
             self._check_packed_address(address, 4)
-            self._ip = int.from_bytes(address, 'big')
+            self._ip = int.from_bytes(address)  # big endian
             return
 
         # Assume input argument to be string or any object representation
@@ -1561,6 +1571,7 @@ class _IPv4Constants:
 
 
 IPv4Address._constants = _IPv4Constants
+IPv4Network._constants = _IPv4Constants
 
 
 class _BaseV6:
@@ -2285,3 +2296,4 @@ class _IPv6Constants:
 
 
 IPv6Address._constants = _IPv6Constants
+IPv6Network._constants = _IPv6Constants
diff --git a/Lib/test/test_ipaddress.py b/Lib/test/test_ipaddress.py
index f012af052..a5388b2e5 100644
--- a/Lib/test/test_ipaddress.py
+++ b/Lib/test/test_ipaddress.py
@@ -102,7 +102,6 @@ class CommonTestMixin_v4(CommonTestMixin):
             "000.000.000.000",
             "192.168.000.001",
             "016.016.016.016",
-            "192.168.000.001",
             "001.000.008.016",
             "01.2.3.40",
             "1.02.3.40",
@@ -1653,7 +1652,7 @@ class IpaddrUnitTest(unittest.TestCase):
         self.assertRaises(IndexError, self.ipv6_scoped_network.__getitem__, 1 << 64)
 
     def testGetitem(self):
-        # http://code.google.com/p/ipaddr-py/issues/detail?id=15
+        # https://code.google.com/p/ipaddr-py/issues/detail?id=15
         addr = ipaddress.IPv4Network('172.31.255.128/255.255.255.240')
         self.assertEqual(28, addr.prefixlen)
         addr_list = list(addr)
@@ -2278,6 +2277,39 @@ class IpaddrUnitTest(unittest.TestCase):
         self.assertEqual(False, ipaddress.ip_address('128.0.0.0').is_loopback)
         self.assertEqual(True, ipaddress.ip_network('0.0.0.0').is_unspecified)
 
+    def testPrivateNetworks(self):
+        self.assertEqual(False, ipaddress.ip_network("0.0.0.0/0").is_private)
+        self.assertEqual(False, ipaddress.ip_network("1.0.0.0/8").is_private)
+
+        self.assertEqual(True, ipaddress.ip_network("0.0.0.0/8").is_private)
+        self.assertEqual(True, ipaddress.ip_network("10.0.0.0/8").is_private)
+        self.assertEqual(True, ipaddress.ip_network("127.0.0.0/8").is_private)
+        self.assertEqual(True, ipaddress.ip_network("169.254.0.0/16").is_private)
+        self.assertEqual(True, ipaddress.ip_network("172.16.0.0/12").is_private)
+        self.assertEqual(True, ipaddress.ip_network("192.0.0.0/29").is_private)
+        self.assertEqual(True, ipaddress.ip_network("192.0.0.170/31").is_private)
+        self.assertEqual(True, ipaddress.ip_network("192.0.2.0/24").is_private)
+        self.assertEqual(True, ipaddress.ip_network("192.168.0.0/16").is_private)
+        self.assertEqual(True, ipaddress.ip_network("198.18.0.0/15").is_private)
+        self.assertEqual(True, ipaddress.ip_network("198.51.100.0/24").is_private)
+        self.assertEqual(True, ipaddress.ip_network("203.0.113.0/24").is_private)
+        self.assertEqual(True, ipaddress.ip_network("240.0.0.0/4").is_private)
+        self.assertEqual(True, ipaddress.ip_network("255.255.255.255/32").is_private)
+
+        self.assertEqual(False, ipaddress.ip_network("::/0").is_private)
+        self.assertEqual(False, ipaddress.ip_network("::ff/128").is_private)
+
+        self.assertEqual(True, ipaddress.ip_network("::1/128").is_private)
+        self.assertEqual(True, ipaddress.ip_network("::/128").is_private)
+        self.assertEqual(True, ipaddress.ip_network("::ffff:0:0/96").is_private)
+        self.assertEqual(True, ipaddress.ip_network("100::/64").is_private)
+        self.assertEqual(True, ipaddress.ip_network("2001::/23").is_private)
+        self.assertEqual(True, ipaddress.ip_network("2001:2::/48").is_private)
+        self.assertEqual(True, ipaddress.ip_network("2001:db8::/32").is_private)
+        self.assertEqual(True, ipaddress.ip_network("2001:10::/28").is_private)
+        self.assertEqual(True, ipaddress.ip_network("fc00::/7").is_private)
+        self.assertEqual(True, ipaddress.ip_network("fe80::/10").is_private)
+
     def testReservedIpv6(self):
 
         self.assertEqual(True, ipaddress.ip_network('ffff::').is_multicast)