Issue 14814: Correctly return NotImplemented from ipaddress._BaseNetwork.__eq__
diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index e788c0a..b1e07fc 100644
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -651,12 +651,12 @@
         return not lt
 
     def __eq__(self, other):
-        if not isinstance(other, _BaseNetwork):
-            raise TypeError('%s and %s are not of the same type' % (
-                             self, other))
-        return (self._version == other._version and
-                self.network_address == other.network_address and
-                int(self.netmask) == int(other.netmask))
+        try:
+            return (self._version == other._version and
+                    self.network_address == other.network_address and
+                    int(self.netmask) == int(other.netmask))
+        except AttributeError:
+            return NotImplemented
 
     def __ne__(self, other):
         eq = self.__eq__(other)