+ /* Add a random number to the old value. This way we can avoid
+ * that two hosts pick the same hostname, win on IPv4 and lose
+ * on IPv6 (or vice versa), and pick the same hostname
+ * replacement hostname, ad infinitum. We still want the
+ * numbers to go up monotonically, hence we just add a random
+ * value 1..10 */
+
+ random_bytes(&a, sizeof(a));
+ u += 1 + a % 10;