Index: protocols/ipv4/ipv4_address.cpp
===================================================================
--- protocols/ipv4/ipv4_address.cpp (revision 40374)
+++ protocols/ipv4/ipv4_address.cpp (working copy)
@@ -448,8 +448,8 @@
        defaultBroadcast->sin_len = sizeof(sockaddr_in);
        defaultBroadcast->sin_family = AF_INET;
        defaultBroadcast->sin_port = 0;
-       defaultBroadcast->sin_addr.s_addr = (address->sin_addr.s_addr & net)
-           | ~net;
+       defaultBroadcast->sin_addr.s_addr = address->sin_addr.s_addr
+           | ~defaultMask->sin_addr.s_addr;
    }

    return B_OK;
Index: stack/interfaces.cpp
===================================================================
--- stack/interfaces.cpp    (revision 40374)
+++ stack/interfaces.cpp    (working copy)
@@ -1327,15 +1327,10 @@
            // Reset netmask and broadcast addresses to defaults
            net_domain* domain = interfaceAddress->domain;
            sockaddr* netmask = NULL;
-           const sockaddr* oldNetmask = NULL;
-           if (option == SIOCSIFADDR) {
-               netmask = InterfaceAddress::Prepare(
-                   &interfaceAddress->mask, address->sa_len);
-           } else {
-               oldNetmask = oldAddress;
-               netmask = interfaceAddress->mask;
-           }

+           netmask = InterfaceAddress::Prepare(
+               &interfaceAddress->mask, address->sa_len);
+
            // Reset the broadcast address if the address family has
            // such
            sockaddr* broadcast = NULL;
@@ -1347,7 +1342,7 @@
                InterfaceAddress::Set(&interfaceAddress->destination, NULL);

            domain->address_module->set_to_defaults(netmask, broadcast,
-               interfaceAddress->local, oldNetmask);
+               interfaceAddress->local, netmask);
        }

        interfaceAddress->AddDefaultRoutes(option);